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Processed Food And Obesity

September 1, 2026 by Dr. Steve Chaney

Why Do Processed Foods Make Us Fat?

Author: Dr. Stephen Chaney

You are probably tired of hearing about how bad processed foods are for you. If you have been following the headlines, you probably already know that diets high in processed foods are linked to obesity, type 2 diabetes, heart disease, some forms of cancer, memory loss, liver disease, kidney disease, depression, risk of dying from any cause, and much more.

And this is a serious problem because 60-70% of the American diet comes from processed foods.

In fact, you may have seen these headlines so frequently that your eyes glaze over, and your mind shuts down any time you see the words “processed foods” in the title.

This week I will be sharing the latest studies on why processed foods make us fat. Stick with me on this. This is not just another article on processed foods. While the focus of the article is on processed foods, the studies it covers are valuable because they also identify some unprocessed foods that can make us fat.

Spoiler alert! Today’s “Health Tip” is important because it teaches us that weight control is not as simple as eliminating processed foods from our diet. We also need to know which unprocessed or minimally processed foods to eat less of.

Before I proceed, I should give you a brief review of how processed foods are defined because that definition has changed in recent years.

What Are Processed Foods?

Everyone used to have a good understanding of which foods were processed. But several years ago, the scientific community introduced a new food classification system called “The NOVA food classification system” and introduced a new category – ultra-processed foods. I have covered this classification system in previous “Health Tips From the Professor” articles, but I will review it here.

The NOVA system categorizes foods into four groups according to the extent of processing they have undergone:

Unprocessed or minimally processed foods.

- This category includes foods like fruit, vegetables, milk, eggs, and meat.

Processed culinary ingredients.

- This category includes foods you might find in restaurants or prepare yourself to which things like salt, sugar, vegetable oils, butter, or cream were added in the preparation.

Minimally processed foods.

- This category includes foods like canned vegetables, freshly made breads, and cheeses.

Ultra-processed foods.

- This category includes foods like soft drinks, chips, packaged snacks, most breakfast cereals, chicken nuggets & fish sticks, fast food burgers, hot dogs, and other processed meats.

The actual list is much longer, but you get the idea. What we used to call processed foods, scientists now call ultra-processed foods. The article I am discussing used the term “ultra-processed foods” in the title.

But, since the term “ultra-processed foods” has not yet entered the popular vocabulary, I will use the term “processed foods” in this article because it is more understandable to the average reader.

Do Processed Foods Make You Fat?

I shared a study in a previous issue of “Health Tips From the Professor” that suggested that the answer was yes but did not answer the question of why. That’s because of the way the experiment was designed.

The ultra-processed diet and unprocessed diets were matched with respect to:

Total calories in the food portions given to the subjects.

Caloric density (calories per serving size). That’s because caloric density has been linked to overeating (I’ll discuss that in more detail below.) The authors of the study eliminated that variable.

Macronutrients (carbohydrate, fat, & protein). I’m sure you’ve seen blogs suggesting that carbohydrates or fat cause weight gain. And you’ve probably seen blogs suggesting that high protein diets cause weight loss. The authors eliminated these variables.

Total sugar, fiber, and sodium. That’s because the sugar, fat, and sodium content of foods increase their tastiness (palatability), which has been linked to overeating (more below). The authors eliminated this variable.

In short, this study compared a tasty, healthy ultra-processed food diet with a tasty, healthy unprocessed food diet. [Note: This does not represent the real world. In the real world the ultra-processed foods eaten by most Americans are higher in caloric density, sugar, fat, and sodium and lower in fiber than unprocessed foods.]

However, in the scientific world, this was an excellent study design. By eliminating variables thought to explain the correlation between ultra-processed food consumption and obesity, the study was able to focus on two questions:

#1: With those variables eliminated, do ultra-processed foods still lead to overeating? Here the answer was a clear, yes.

The study participants eating ultra-processed foods ate 500 more calories per day than those eating unprocessed foods. (Both groups were presented with meals and snacks containing the same number of calories and told to eat as much as they wanted.)

Participants eating ultra-processed foods gained 2 pounds in just two weeks, while those eating unprocessed foods lost 2 pounds.

#2: If so, what else about ultra-processed foods leads to overeating? One popular theory of why ultra-processed foods lead to overeating is that they cause large blood sugar spikes and crashes, which stimulates appetite. But the authors of the study were disappointed to find no large blood sugar spikes following consumption of ultra-processed food meals.

So, why did the ultra-processed food group eat more in this study? This study did not provide an answer to that question, but other studies (described below) have provided probable answers to that question.

Processed Food And Obesity

What do other studies tell us about why processed foods make us overeat and gain weight? Here are the top 7 mechanisms that have been suggested and what they mean for us.

#1: Caloric Density: Simply put, caloric density is the number of calories in a serving of food. When you consume foods with a high caloric density, you are more likely to consume excess calories without even thinking about it.

When I was still teaching medical students, I used this example to illustrate the effect of caloric density on calories consumed. “There are the same number of calories in a 2-ounce candy bar and a pound of apples. You can eat a 2-ounce candy bar and be ready to eat more. If you eat a pound of apples, you are done for a while”.

Since most processed foods have a higher caloric density than unprocessed foods, the simplest solution to weight control is to limit processed foods in your diet.

However, how you or your favorite restaurant prepares unprocessed foods is important as well. For example, the addition of cheese or cream sauces can significantly increase the caloric density of the food. This is why the NOVA food classification system I described above created a new category of “culinary foods” to describe these kinds of foods.

#2: Hyper-palatability: In prehistoric times foods that were sweet, salty, and fatty were essential for survival, so we are hardwired to desire those foods. Here is why:

We need a certain amount of sugar for our brain, red blood cells, and a few other tissues to function. Wild game provides almost no carbohydrate. Fruits were the best source of sugar, but fruits were scarce prior to farming. The craving for sweetness drove us to forage far and wide to find fruits and other plant sources of sugar and carbohydrate.

Sodium is essential for survival, but unprocessed plant and animal foods provide very little. That’s why even in Biblical times, salt was worth its weight in gold.

In prehistoric times, food was sometimes scarce, especially in winter. It might be a week or more between meals. Fat stores got prehistoric man through these times of scarcity, so it was important to eat fatty meals in times of plenty. [Note: We no longer live in times of scarcity, and those fat stores have gone from being an asset to being a health concern.]

Unfortunately, “Big Food, Inc” has weaponized these hardwired desires for sweet, salty, and fatty foods. Simply put, processed foods taste good because they fulfil our hardwired taste desires. Scientists call it “hyper-palatability”. But whatever you call it, we want to eat more, and that leads to overeating.

And again, the way we prepare the foods we eat also matters. It’s only natural to add extra salt, sugar, and/or fat to the foods we prepare so they taste better. And if we add too much, we make the healthy foods we eat hyper-palatable, and we are tempted to overeat.

On a personal note, I never knew you might want to add sugar and fat to the vegetables you cook before my family moved to the south. On the other hand, I had never eaten collard greens before either.

#3: Food Consistency: When you look at studies on the effect of food consistency on calories consumed, you find that there are several different ways of defining food consistency, but they are all looking at the same thing from a different perspective – like the fable of the 6 blind men trying to describe an elephant.

Food Structure: The classic study, published in 2009, compared the effect of sliced apples, applesauce, and apple juice eaten shortly before a meal on the number of calories consumed at the meal. In terms of calories consumed during the meal, the results were clear. It was apple juice > applesauce > apple slices.

This drew attention to the effect of food structure on calories consumed. Apples are a whole food with cellular structure intact. Applesauce contains all the nutrients, phytonutrients, and fiber of whole apples, but the cellular structure has been lost. Apple juice contains most of the nutrients and phytonutrients of applesauce, but the fiber has been lost.

Why does the structure of whole foods matter?

Cell structure must be destroyed before digestion can occur, the release of sugar and carbohydrates from the food is delayed. This reduces the spikes and valleys of blood sugar that can increase appetite.

Transit time of the food through the intestine is also delayed. Thus, the feeling of fullness persists longer, which reduces appetite.

There are two takeaway lessons from this study that may not be so obvious:

Neither applesauce nor apple juice meet the NOVA definition of an ultra-processed food. So, simply removing processed foods from your diet may not be enough to reduce your appetite and, therefore, your caloric intake.

In addition, adding fiber back to apple juice did not make it equivalent to applesauce in reducing appetite. So, despite what Big Food Inc tells you, adding fiber to processed foods does not turn them into health foods.

Soft Versus Hard Foods: Many processed foods are soft, and most unprocessed foods are hard. So, you could think of this as a description that separates processed foods from unprocessed foods.

But, if you consider the apples versus applesauce comparison I described above, it is obvious that soft versus hard description also pertains to minimally processed foods such as applesauce and whole, unprocessed foods such as apples.

For example, one recent study comparing soft versus hard foods found it didn’t matter whether the soft foods were processed or unprocessed. People in the study ate more calories from all soft foods than from hard, unprocessed foods such as raw fruits and vegetables.

Fast Versus Slow Foods: This description separates foods based on the speed at which they are digested and pass through the intestine. Once again, you might think of this as a description that separates processed and unprocessed foods until you think about applesauce versus apples comparison.

And, as you might expect, a recent study comparing “fast” versus “slow” foods found it didn’t matter whether the fast and slow foods were processed or unprocessed. People in the study ate more calories from fast foods than from slow foods.

[Note: This study defined “slow” foods as harder, chunkier, more solid, and more viscous. While the first three adjectives describe what other scientists also refer to as “hard” foods, the final adjective broadens the category to include “soft” foods like oatmeal.]

How Can You Enjoy Eating Without Getting Fat?

For most Americans, weight is a constant uphill battle. Their weight increases by a few pounds every year, and over time that continuing weight gain adds up. Diets are never enjoyable, which is part of the reason they almost always fail in the long term. You want to control your weight, but you also want to enjoy what you eat. Why is that so hard?

The secret to a healthy weight is to find foods you enjoy that don’t increase your appetite – foods that fill you up, so you eat less naturally. Here are my 4 tips for eating foods you enjoy without getting fat.

Tip #1: Limit processed foods. Processed foods tend to have a high caloric density; are hyper-palatable, soft, and fast; and lack the intact cellular structure of whole, unprocessed foods. And multiple studies, such as the one I cited above, agree that processed foods cause us to eat more and to gain weight. So, the single most important step you can take to control your weight is to limit your intake of processed foods.

Tip #2: Choose minimally processed foods wisely. The studies I shared above suggest that avoiding processed foods may not be enough. We also need to look at the minimally processed foods we eat (applesauce, for example). These studies suggest we should also favor whole, unprocessed foods over minimally processed foods that are softer and faster (more quickly digested).

By now, you might be saying, “Wait a minute. I thought you said I could enjoy eating without getting fat. How can I enjoy eating if I have to give up my favorite processed and minimally processed foods?”

My short answer would be, “No. But you might want to broaden your horizons”. We all tend to be creatures of habit. We eat a relatively small variety of foods on a regular basis. When my wife and I decided to eat healthier, we kept trying new foods until we found new, healthier foods we loved.

The category of whole unprocessed foods offers many options. There are fruits, vegetables, many varieties of 100% whole grains, beans, nus, seeds, eggs, and meats. And we are blessed to live in a country with abundant choices. When you walk into your local supermarket you will find dozens of foods in each of these categories that you have never tried before. Be daring. Keep trying new foods until you find new favorite foods you love.

Tip #3: Be aware of how foods are prepared. The studies described above also suggest how we prepare the food is important. We can start out with a whole unprocessed food and end up with something no better than processed food if we prepare it incorrectly.

If we add lots of cream, cheese, butter, and/or sugar, we increase the caloric density. And this can lead to us consuming more calories without even thinking about it.

Throw in some salt and we have also made the food hyper-palatable, which makes us want to eat more.

Now you might be saying, “But I grew up with my food being cooked this way. This is my comfort zone. Do I have to completely change the way I cook my food, and the items I choose at my favorite restaurant?”

Again, my short answer would be, “No, but you might want to try new recipes.” I am not a cooking guru. That would be my wife. But I do know there are lots of books and web sites featuring healthy recipes. Once again, be bold. Try new recipes until you find new favorites. Try new items on your favorite restaurant’s menu or try new restaurants until you find healthier, restaurant foods you love.

Tip #4: Never say never. This is perhaps the most important tip. Whenever we tell ourselves we can never eat a food again, it becomes irresistible. We are setting ourselves up for failure. The goal should be to change unhealthy foods and unhealthy recipes from an everyday occurrence to an occasional pleasure.

The Bottom Line

Multiple studies show that eating processed foods leads to weight gain. It may be no coincidence that 60-70% of the foods Americans eat is highly processed and 60-70% of us are overweight or obese.

In the article above, I summarize recent studies asking why processed foods make us fat. If you think these studies are only of interest to scientists, you would be wrong. These studies also help us to identify unprocessed and minimally processed foods in our diet that can make us fat.

For more information on these studies, and 4 tips on how you can enjoy eating without getting fat, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

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About The Author

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years. Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.

Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 54 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Is Whole Fat Dairy Healthy?

August 29, 2023 by Dr. Steve Chaney

Is It Dairy Or Diet?

Author: Dr. Stephen Chaney

For years we have been told to select low fat dairy foods. But recent headlines claim, “That’s nonsense. Whole fat dairy foods are healthy.” Are those headlines true?

In previous issues of “Health Tips From the Professor” I have kept you abreast of recent studies suggesting that whole fat dairy foods may not be as bad for us as we thought. I also cautioned you that the headlines may not have accurately represented the studies they described.

Headlines have to be simple. But truth is often more nuanced. If we believed the current headlines, we might be asking ourselves questions like, “Should we ditch the current health guidelines recommending low-fat dairy foods? Are foods like ice cream, sour cream, and cheddar cheese actually be good for us?

To answer these questions, I will look at the study (A Mente et al, European Heart Journal, 44, 2560-2579, 2023) behind the current headlines and put the study into perspective.

Spoiler alert: If I could summarize the study findings in two sentences, they would be, “Whole fat dairy can be part of a healthy diet. But can it be part of an unhealthy diet?”

Stay tuned. I will discuss the science behind that statement below.

How Was This Study Done?

This study started with data collected from the Prospective Urban Rural Epidemiology (PURE) study. The PURE study is an ongoing study correlating diet, lifestyle, and environmental effects on health outcomes. It has enrolled 166,762 individuals, age 35-70, from 21 low-, middle-, and high-income countries on 5 continents.

Habitual food intake was determined using country-specific food frequency questionnaires at the time participants joined the study. Participants (166,762) from the PURE study who had complete dietary information were included in this study and were followed for an average of 9.3 years.

Based on preliminary analysis of data from the PURE study, the authors developed their version of a healthy diet, which they call the PURE diet. Like most other healthy diets, the PURE diet emphasizes fruits, vegetables, legumes, nuts, and fish. However:

Based on studies suggesting that whole fat dairy foods can be part of a healthy diet, the PURE diet includes whole fat dairy foods.

This is different from most other healthy diet recommendations.

They went on to develop what they referred to as the PURE healthy diet score by:

Determining the median intake for each of the 6 food groups included in their PURE diet (fruits, vegetables, legumes, nuts, fish, and whole fat dairy).

Assigning each participant in the study a score of 0 or 1 depending on whether their intake for that food group was below or above the median intake.

Adding up the points. Since 6 food groups were included in the PURE diet, this means that each participant in the study was assigned a PURE diet score ranging from 0-6.

Once they had developed a PURE diet score, they expanded their data by including five additional large independent studies that included people from 70 countries. The combined data from all six studies amounted to 245,597 people from 80 countries. Of the people included in the data analysis:

21% came from high income countries.
60% came from middle income countries.
19% came from low-income countries.

This is very similar to the global population distribution. This is a strength of this study because it allowed them to ask whether the PURE diet score worked as well in low-income countries as in high-income countries.

Finally, they correlated the PURE diet score with outcomes like all-cause mortality, heart attack, and stroke.

Is Whole Fat Dairy Healthy?

The authors of this study divided the participants of all 6 studies into quintiles based on their PURE diet score and compared those in the highest quintile (PURE score of ≥ 5) with those in the lowest quintile (PURE score of ≤ 1).

The people in the highest quintile were eating on average 5 servings/day of fruits and vegetables, 0.5 servings/day of legumes, 1.2 servings/day of nuts, 0.3 servings/day of fish, 2 servings/day of dairy (of which 1.4 servings/day was whole fat dairy), 0.5 servings/day of unprocessed red meat, and 0.3 servings/day of poultry.

The people in the lowest quintile ate significantly less fruits, vegetables, nuts, fish, and dairy; and slightly less legumes, unprocessed red meat, and poultry than those in the highest quintile.

However, they consumed significantly more refined wheat foods and white rice. This study did not track consumption of highly processed foods, but the high consumption of white flour leads me to suspect they ate a lot more highly processed food.

With that in mind, when the authors compared people with the highest PURE diet scores to those with the lowest PURE diet scores:

All-cause mortality was reduced by 30%.

Cardiovascular disease was reduced by 18%.

Heart attacks were reduced by 14%.

Strokes were reduced by 19%.

The PURE healthy eating score was slightly better at predicting health outcomes than the Mediterranean, DASH, and HEI (Healthy Eating Index) scores. But the differences were small. So, I still recommend choosing the healthy diet that best fits your preferred foods and your lifestyle.

The PURE healthy eating score was significantly better at predicting health outcomes than the Planetary diet score. I will discuss the nutritional inadequacy of “sustainable diets” like the Planetary diet in next week’s “Health Tips From the Professor” article.

Because of the size and design of this study, they were able to make three interesting observations.

The PURE, Mediterranean, DASH, and HEI diet scores were predictive of health outcomes in every country across the globe. You no longer have to wonder if what works in the United States will work in low-income countries and in countries with very different food preferences. Previous studies have not been able to make that claim.

2) You don’t have to be perfect.

- A 20% increase (one quintile) in PURE score was associated with a 6% lower risk of major cardiovascular events and an 8% lower risk of mortality. In other words, even small improvements in your diet may improve your health outcomes.

- The health benefits of the PURE diet started to plateau at a score of 3 (with 6 being the highest score). The authors concluded that most of the health benefits were associated with a modestly higher consumption of healthy foods compared to little or no consumption of healthy foods.

Simply put, that means the health benefits gained by going from a moderately healthy diet to a very healthy diet are not as great as the health benefits gained by going from a poor diet to a moderately healthy diet.

[Note: There are still improvements in health outcomes when you go from a moderately healthy diet to a very healthy diet. My recommendation: “You don’t need to achieve perfection, but you shouldn’t accept mediocrity”.]

3) The PURE diet score was more predictive of health outcomes in some countries than in others.

- The PURE diet score was more predictive of health outcomes in low-income countries. The authors felt that was because low-income countries started with average PURE scores of 2.1, whereas higher-income countries started with average PURE scores of 3.5.

The authors felt this was another example getting more “bang for the buck” by going from a poor diet to a moderately healthy diet than from a moderately healthy diet to a very healthy diet. (Remember, the health benefits associated with improving PURE diet scores start to plateau at a PURE score of 3.

- The difference in benefits for low-income countries compared to high-income countries was observed for the Mediterranean, DASH, and HEI diet scores. So, it is probably safe to say for any healthy diet you don’t need to be perfect. You just need to be better.

The authors concluded, “A diet composed of higher amounts of fruit, vegetables, nuts, legumes, fish, and whole fat dairy is associated with a lower risk of cardiovascular disease and mortality in all world regions, especially in countries with lower income where consumption of these foods is low.”

Is It Dairy Or Diet?

The headlines are telling us that recommendations to choose low-fat dairy products are out of date. They say there is no reason to fear whole fat dairy foods. They are good for you. Bring on the ice cream, sour cream, cream cheese, and high fat hard cheeses!

As usual, there is a kernel of truth in the headlines, but headlines have to be simple. And the latest headlines are an oversimplification of what the studies actually show. Let me provide perspective to the headlines by asking two questions.

#1: Is it dairy or diet? A major weakness of this and similar studies is that they fail to consider diet context. What do I mean by that? Let’s dig a little deeper into this study.

Let’s start with a description of the PURE diet. It is a diet that emphasizes fruits, vegetables, legumes, nuts, and fish. In other words, it is a primarily plant-based diet.

Although the authors keep referring to the diet as one that includes whole fat dairy. It would be more accurate to say that it includes dairy, which was 30% low-fat and 70% whole fat.

The authors said that removal of any one food group from this combination reduced the predictive power of the PURE diet. In other words, the beneficial effect of 70% whole fat dairy is best seen in the context of a primarily plant-based diet.

The PURE diet was most effective at predicting health outcomes in low-income countries where a significant percent of the population consumes a primarily plant-based diet because meats are expensive.

So, a more accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet. But that is too complicated for a headline.

#2: If whole fat dairy can be part of a healthy diet, can it also be part of an unhealthy diet?

To answer that question let’s compare the potential effects of whole fat dairy on a primarily plant-based diet compared to the typical American or European diet.

Milk and other dairy foods are excellent sources of calcium, vitamin B12, and iodine and good sources of protein, vitamin D, choline, zinc, and selenium – nutrients that are often low or missing in plant-based diet. And this is true whether the dairy foods are low-fat or whole fat.

Primarily plant-based diets tend to be low in saturated fat, so the potential negative effects of adding a small amount of saturated fat to the diet may be outweighed by the beneficial effects of the nutrients dairy foods provide.

On the other hand,

The typical American or European diet provides plenty of protein and vitamin B12 and significantly more choline, vitamin D, iodine, and zinc than a plant-based diet. The added nutrients from adding dairy foods to this kind of diet is still beneficial, but the benefits are not as great as adding dairy foods to a primarily plant-based diet.

If you read the American Heart Association statement on saturated fats, it does not say that any amount of saturated fat is bad for you. In fact, small amounts of saturated fats play some beneficial roles in our bodies. The American Heart Association says, “Eating too much saturated fat can raise the level of LDL cholesterol in your blood…[which] increases your risk of heart disease and stroke.”

Here is where the problem lies. The typical American or European diet already contains too much saturated fat. Whole fat dairy just adds to that excess.

So, the most accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet but may not be a healthy addition to the typical American diet. But that is way too complicated for a headline.

You are probably wondering what this means for you. Here are my recommendations.

If you eat like most Americans, you should continue to follow the current health guidelines to choose low-fat dairy foods.

If you happen to be among the few Americans who eat a primarily plant-based diet, you will probably benefit by adding a mixture of low-fat and whole fat dairy foods to your diet.

The Bottom Line

Once again, the headlines are telling us that recommendations to choose low-fat dairy products are out of date. The articles say there is no reason to fear whole fat dairy foods. They are good for you. Bring on the ice cream, sour cream, cream cheese, and high fat hard cheeses!

As usual, there is a kernel of truth in the headlines, but headlines have to be simple. And the latest headlines are an oversimplification of what the studies actually show. In this post I looked at the study behind the most recent headlines and provided perspective to the headlines by asking two questions.

#1: Is it dairy or diet? A major weakness of this and similar studies is that they fail to consider diet context.

When you consider diet context a more accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet. But that is too complicated for a headline.

#2: If whole fat dairy can be part of a healthy diet, can it also be part of an unhealthy diet?

When you consider that question the most accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet but may not be a healthy addition to the typical American diet. But that is way too complicated for a headline.

You are probably wondering what this means for you. Here are my recommendations.

If you eat like most Americans, you should continue to follow the current health guidelines to choose low-fat dairy foods.

If you happen to be among the few Americans who eat a primarily plant-based diet, you will probably benefit by adding a mixture of low-fat and whole fat dairy foods to your diet.

For more information on this study, and the science behind my summary of the study, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

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For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Does Olive Oil Help You Live Longer?

March 8, 2022 by Dr. Steve Chaney

Which Fat Is Healthiest?

Author: Dr. Stephen Chaney

If you believe the headlines, olive oil is a superfood. It is often described as the star of the Mediterranean diet. It is referred to as the healthiest of dietary fats. Is this true, or is it hype?

Olive oil’s resume is impressive:

It is rich in monounsaturated fatty acids, which…

- Are less susceptible to oxidation than polyunsaturated oils.

- Make our arteries more flexible, which lowers blood pressure.

- Lower LDL-cholesterol levels, which reduces the risk of heart disease.

Extra-virgin olive oil contains phytonutrients and tocopherols (various forms of vitamin E), which…

- Have anti-inflammatory properties.

- Improve insulin sensitivity and blood sugar control.

Olive oil consumption is also associated with healthier gut bacteria, but it is not clear whether this is due to olive oil or to the fact that a Mediterranean diet is also richer in fresh fruits, vegetables, and whole grains.

Several recent studies have shown that olive oil consumption is associated with a lower risk of heart disease. However, these studies were conducted in Mediterranean countries where the average intake of olive oil (3 tablespoons/day) is much greater than in the United States (0.3 tablespoons/day).

The current study (M Guasch-Ferré et al, Journal of the American College of Cardiology, 79: 101-112, 2022) was designed to test whether:

The amount of olive oil Americans consume decreases the risk of heart disease.

Whether olive oil consumption had benefits beyond a reduction in heart disease risk.

How Was This Study Done?

This study combined data from 60,582 women enrolled in the Nurses’ Health Study and 31,801 men enrolled in the Health Professionals Follow-Up Study). The participants:

Were free of heart disease and diabetes at the start of the study.

Were 56 at the start of the study with an average BMI of 25.6 (Individuals with BMIs in the 25-30 range are considered overweight, so they were at the lowest end of the overweight range).

The Nurses’ Health Study and Health Professional Follow-Up Study are both association studies, meaning they looked at the association between olive oil consumption and health outcomes. They cannot directly prove cause and effect. However, they are very strong association studies because:

Every 2 years, participants filled out a questionnaire that updated information on their body weight, smoking status, physical activity, medications, multivitamin use, and physician-diagnosed diseases.

Every 4 years, participants filled out a comprehensive food frequency questionnaire.

In other words, this study did not just rely on the participant’s lifestyle, dietary intake, and health at the beginning of the study, as so many association studies do. It tracked how each of these variables changed over time.

The participants were followed for an average of 28 years and their average olive oil intake over those 28 years was correlated with all-cause mortality and mortality due to specific diseases.

Deaths were identified from state vital statistics, the National Death index, reports by next of kin, or reports by postal authorities.

Causes of death were determined by physician review of medical records, medical reports, autopsy reports, or death certificates.

Does Olive Oil Help You Live Longer?

During the 28 years of this study:

Olive oil consumption in the United States increased from an average of ~1/3 teaspoon/day to ~1/3 tablespoon/day.

Margarine consumption decreased from 12 g/day to ~4 g/day.

The consumption of all other fats and oils remained about the same.

As I mentioned above, olive oil consumption was averaged over the life of the study for each individual. When the investigators compared people consuming the highest amount of olive oil (>0.5 tablespoon/day) with people consuming the least olive oil (0 to 1 teaspoon/day):

Mortality from all causes was decreased by 35% for the group consuming the most olive oil.

However, the group consuming the most olive oil also was more physically active, had a healthier diet, and consumed more fruits and vegetables than the group who consumed the least olive oil.

After correcting for all those factors, mortality from all causes was decreased by 19% for the group consuming the most olive oil.

The authors concluded, “We found that greater consumption of olive oil was associated with lower risk of total…mortality… Our results support current dietary recommendations to increase the intake of olive oil…to improve overall health and longevity.” (I will fill in the blanks in this statement once I have covered other aspects of this study)

The authors also said, “Of note, our study showed that benefits of olive oil can be observed even when consumed in lower amounts than in Mediterranean countries.”

Are There Other Benefits From Olive Oil Consumption?

The study didn’t stop there. The investigators also looked at the effect of olive oil consumption on the major killer diseases in the United States and other developed countries. When they compared the effect of olive oil consumption on cause-specific mortality, they found that the group who consumed the most olive oil reduced their risk of dying from:

Cardiovascular disease by 19%.

Cancer by 17%

Respiratory disease by 18%.

Neurodegenerative disease (cognitive decline and Alzheimer’s disease) by 29%.

- The reduction in neurodegenerative disease was much greater for women (34% decrease) than for men (19% decrease).

With this information I can fill in one of the blanks in the author’s conclusions: “We found that greater consumption of olive oil was associated with lower risk of total and cause-specific mortality… Our results support current dietary recommendations to increase the intake of olive oil…to improve overall health and longevity.”

Which Fats Are Healthiest?

The sample size was large enough and the dietary information complete enough for the investigators to also estimate the effect of substituting olive oil for other dietary fats and oils.

They found that every ¾ tablespoon of olive oil substituted for an equivalent amount of:

Margarine decreased total mortality by 13%.

Butter decreased total mortality by 14%.

Mayonnaise deceased total mortality by 19%

Dairy fat decreased total mortality by 13%.

- The same beneficial effects of substituting olive oil for other fats were seen for cause-specific mortality (cardiovascular disease, cancer, respiratory disease, and neurodegenerative disease).

- There was a linear dose-response. This means that substituting twice as much olive oil for other dietary fats doubled the beneficial effects on total and cause-specific mortality.

However, substituting olive oil for polyunsaturated vegetable oils had no effect on total and cause-specific mortality.

Now I can fill in the remaining blanks in the author’s conclusion: “We found that greater consumption of olive oil was associated with lower risk of total and cause-specific mortality. Replacing other types of fat, such as margarine, butter, mayonnaise, and dairy fat, with olive oil was also associated with a lower risk of mortality. Our results support current dietary recommendations to increase the intake of olive oil and other unsaturated vegetable oils in place of other fats to improve overall health and longevity.”

What Does This Study Mean For Us?

As I said above, this is an association study, and association studies do not prove cause and effect. However:

1) This is a very strong association study because:

- It is a very large study (92,383 participants).

- It followed the participants over a long time (28 years).

- It utilized a very precise dietary analysis.

- Most importantly, it tracked the participant’s lifestyle, dietary intake, and health at regular intervals throughout the study. Most association studies only measure these variables at the beginning of the study. They have no idea how they change over time.

2) This study is consistent with several previous studies showing that olive oil consumption decreases the risk of dying from heart disease.

3) This study draws on its large population size and precise dietary analysis to strengthen and extend the previous studies. For example:

- The study showed that increased olive oil consumption also reduced total mortality and mortality due to cancer, respiratory disease, and neurodegenerative disease.

- The study measured the effect of substituting olive oil for other common dietary fats.

- The study showed that increased olive oil consumption in the context of the American diet was beneficial.

I should point out that the headlines you have seen about this study may be misleading.

While the headlines may have depicted olive oil as a superfood, this study did not find evidence that olive oil was more beneficial than other unsaturated vegetable oils. Again, this is consistent with many previous studies showing that substituting vegetable oils for other dietary fats reduces the risk of multiple diseases.

The headlines focused on the benefits of increasing olive oil consumption. However, they neglected the data showing that increasing olive oil (and other vegetable oils) was even more beneficial (35% reduction in total mortality) in the context of a healthy diet – one with increased intake of fruits, vegetables, whole grains, nuts, legumes, and long-chain omega-3s and decreased intake of red & processed meats, sodium, and trans fats.

So, my recommendation is to follow a whole food, primarily plant-based diet and substitute extra-virgin olive oil and cold pressed vegetable oils for some of the animal fats in your diet.

Some vegan enthusiasts recommend a very low-fat whole food plant-based diet. They point to studies showing that such diets can actually reverse atherosclerosis. However:

Those studies are very small.

The overall diet used in those studies is a very healthy plant-based diet.

The studies did not include a control group following the same diet with olive oil or other vegetable oils added to it, so there is no comparison of a healthy vegan diet with and without vegetable oils.

If you have read my book, “Slaying the Food Myths”, you know that my recommendations encompass a variety of whole food, primarily plant-based diets ranging all the way from very-low fat vegan diets to Mediterranean and DASH diets. Choose the one that best fits your food preferences and the one you will be most able to stick with long term. You will be healthier, and you may live longer.

The Bottom Line

A recent study looked at the effect of olive oil consumption on the risk dying from all causes and from heart disease, cancer, respiratory disease, and neurodegenerative diseases. When the study compared people consuming the highest amount of olive oil (>0.5 tablespoon/day) with people consuming the least olive oil (0 to 1 teaspoon/day):

Mortality from all causes was decreased by 19% for the group consuming the most olive oil.

They also found that the group who consumed the most olive oil reduced their risk of dying from:

Cardiovascular disease by 19%.

Cancer by 17%

Respiratory disease by 18%.

Neurodegenerative disease (cognitive decline and Alzheimer’s disease) by 29%.

They also found that every ¾ tablespoon of olive oil substituted for an equivalent amount of:

Margarine decreased total mortality by 13%.

Butter decreased total mortality by 14%.

Mayonnaise deceased total mortality by 19%

Dairy fat decreased total mortality by 13%.

However, substituting olive oil for polyunsaturated vegetable oils had no effect on total and cause-specific mortality.

The authors concluded, “We found that greater consumption of olive oil was associated with lower risk of total and cause-specific mortality. Replacing other types of fat, such as margarine, butter, mayonnaise, and dairy fat, with olive oil was also associated with a lower risk of mortality. Our results support current dietary recommendations to increase the intake of olive oil and other unsaturated vegetable oils in place of other fats to improve overall health and longevity.”

For more details and a summary of what this study means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Is Margarine Healthier Than Butter?

February 22, 2022 by Dr. Steve Chaney

What Should You Put On Your Toast?

Author: Dr. Stephen Chaney

The Checkered History Of Margarine

Many of you may have seen the recent headlines proclaiming that a recent study has shown that margarine is healthier than butter.

Some of you may be saying, “I don’t believe it.”

Others may be saying, “Of course. Hasn’t that always been true.”

So, to clear up the confusion, let me share a brief history of margarine.

Margarine was invented in 1869 by a French chemist in response to a request from Napoleon III to create a poor man’s butter substitute. Napoleon’s intentions weren’t entirely altruistic. He also wanted a cheaper butter substitute for his armies.

Margarine initially encountered a strong headwind in this country. The dairy lobby influenced congress and state legislatures to pass numerous laws designed to increase the cost and reduce the desirability of margarine.

In the 1950s the ground started to shift. Scientists and the medical community started to recognize that saturated fats were a major contributor to heart disease. Suddenly, butter became a villain, something to avoid.

- But that was a problem. Butter was preferred spread for bread and toast. It was used for cooking. It was ubiquitous. You may even remember the popular “I like bread and butter” song. What was a person to do?

At that time margarine was made by partially hydrogenating vegetable oils (usually corn oil because it was the cheapest). The hydrogenation converted some of the unsaturated fats in vegetable oils to saturated fats so that margarine would not be in liquid form at room temperature. However, the total amount of saturated fat in margarine was less than in butter, and the ratio of polyunsaturated fat to saturated fats was much healthier. Margarine took on a new luster. It was now the healthier alternative to butter.

- Once margarine attained the “healthier” status, most of the anti-margarine laws were quickly abolished, and margarine quickly outpaced butter as the spread of choice.

In the 1980s the ground shifted again. A French study found the margarine increased the risk of heart disease more than butter. Further studies showed that the hydrogenation process created a novel type of fat called trans fats. By the 1990s it was widely accepted that trans fats increased the risk of heart disease even more than saturated fats.

- Margarine became the villain, and butter was considered the more natural, healthier spread. By 2000 sales of butter once more surpassed those of margarine.

In 2018 the ground shifted once again. After almost 20 years of deliberation, the FDA banned trans fats from the American food supply as of 2018. Margarine no longer contained trans fats.

Today’s study (C Weber et al, Public Health Nutrition, doi:10.1017/S1368980021004511) asks whether the reformulated, trans-fat-free margarines are once again a healthier alternative to butter.

Is Margarine Healthier Than Butter?

The study analyzed the fat composition of 53 margarine tub or squeeze products, 18 margarine stick products, 12 margarine-butter blend products and compared them with the fat composition of butter. The results are shown below:

There was no detectable trans fat in any of the margarine products. So, based on saturated fat content and the ratio of unsaturated fats to saturated fats, the margarine products were all healthier than butter. This is what the paper concluded.

	Mean % of Total Fat In:
	Margarine Tub or Tube	Margarine Sticks	Margarine- Butter Blends	Butter
SFA*	29%	38%	38%	60%
MUFA*	36%	34%	43%	26%
PUFA*	33%	29%	13%	4%
*SFA = Saturated fats, MUFA = Monounsaturated fats, PUFA = Polyunsaturated fats

But let’s look a bit deeper. First, we should look at the fat sources.

The saturated fat in the margarine products comes from either palm or coconut oil. There are claims that these plant saturated fats may be healthier than saturated fats from animal sources. But there are no long-term studies to back up those claims, So, I will simply consider them equivalent to any other saturated fat for this review.

Next, we should look at the labels.

The labels of most butter products are simple. Butter is sweet cream and salt. Unsalted butter is sweet cream and natural flavoring (usually lactic acid). This is the way that butter has been made for hundreds of years.

Margarine products are manufactured foods. They didn’t come from a cow. Their labels are significantly longer. And you should read the labels carefully.

- Some margarine products are made with natural ingredients.

- However, many margarine products contain preservatives and artificial flavors.

So, choosing between margarine products and butter is not as simple as looking at saturated fat content alone.

But what if you didn’t have to choose between margarine and butter? What if there were other options to consider?

What Should You Put On Your Toast?

Once you decide to look beyond margarine and butter you will find lots of healthy options. For example:

If you have ever eaten at a fine Italian or Greek restaurant, you may have had your bread served with olive oil to dip it in. Of course, this may be a better option for lunch and dinner than for breakfast. (I don’t think jam would pair well with olive oil.)

Nut butters are an excellent choice any time of day. Peanut and almond butters are the most popular, but there are many other nut butters to choose from.

Avocado is another excellent choice.

This just scratches the surface. There are healthier options for almost every palate.

If you look at the fat composition of my top four suggestions, you can readily see why they are healthier choices than either margarine or butter. They are much lower in saturated fat and high in heart healthy monounsaturated and polyunsaturated fats.

	Mean % of Total Fat In:
	Olive Oil	Almond Butter	Peanut Butter	Avocado
SFA*	14%	9%	22%	16%
MUFA*	74%	64%	53%	71%
PUFA*	12%	27%	25%	13%
*SFA = Saturated fats, MUFA = Monounsaturated fats, PUFA = Polyunsaturated fats

But that is just part of the story:

Nut butters are also a good source of protein. And both nut butters and avocados provide nutrients, phytonutrients, and fiber you don’t find in margarine or butter.

There are also labels to consider:

Avocados are whole foods and don’t require labels. There are no other ingredients. What you see is what you get.

Olive oil is a bit more complicated. It is often blended with cheaper oils to reduce the cost, and that doesn’t always show up on the label. My best advice is to get extra virgin olive oil from a brand you trust.

With nut butters, you should read the label. For example, the ingredient label for almond butter should list almonds as the sole ingredient. Peanut butter should just list peanuts. However, some brands add other oils, sugar, emulsifying agents, etc. These are the brands you should leave on the shelf.

Our “go-to” spread is almond butter. I like it with cinnamon sprinkled on top, although sliced bananas and cinnamon is another excellent choice.

As for butter, we still like it on baked sweet potatoes and corn on the cob. We freeze our butter and cut off a slice whenever we need it. A stick of butter lasts us many months.

The Bottom Line

Now that trans fats have been removed from margarine products a recent study revisited the question as to whether margarine or butter was the healthier choice. On the basis of their saturated fat content, the study concluded that margarine products were healthier than butter.

However, that is just part of the story. When you look at the labels:

The labels of most butter products are simple. Butter is sweet cream and salt. Unsalted butter is sweet cream and natural flavoring (usually lactic acid). This is the way that butter has been made for hundreds of years.

Margarine products are manufactured foods. They didn’t come from a cow. Their labels are significantly longer. And you should read the labels carefully.

So, choosing between margarine products and butter is not as simple as looking at saturated fat content alone. But what if you didn’t have to choose between margarine and butter? What if there were other options to consider?

Once you decide to look beyond margarine and butter you will find lots of healthy options. I discuss my top 4 choices above.

For more details, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.