Debunking diet myths with Dr. Rosanne Farris

There’s so much advice on nutrition and health these days that it can confuse just about anyone. Add in reports of chronic diseases and the lure of new trends and it’s hard to differentiate between accurate health recommendations with quick fixes, fads and miracle tricks. Since there seems to be a new trend out nearly every month, I decided to write about this issue, debunking some popular diet fads. I asked my mother, a super-smart, science-loving, expert-in-public health to weigh in and set the record straight! In this blog, I identify a few common questions and myths to get evidence-based answers, but first, some background info about my mom.

Dr. Rosanne P. Farris has dedicated her decades long career in studying public health. She spent 25 years in Applied Nutrition Research studying Diet relating to Chronic Diseases and 16 years at Centers for Disease Control (that’s the CDC!) in Public Health Nutrition and Prevention of Heart Disease and Obesity. She’s a Registered Dietitian with Academy of Nutrition and Dietetics and holds a Master’s degree in Public Health Nutrition and Doctorate in Health Promotion.

Now let’s identify some problems in diet trends. There seem to be a lot of harmful myths out there, let’s break down some common ones.

  1. Why are many diet trends not useful or sometimes harmful?

RF: The American diet industry is $60 billion. $60 BILLION! If we had a fraction of those resources dedicated to answering scientific questions about nutrition and health, we’d have more complete answers and better understanding of the complexities of human nutrition. What we have now is the media “translating” the latest new piece of the puzzle, the last study, and the industry and public jumping on board to the latest, greatest trend. The diet and supplement industry is largely unregulated with little consumer protection. Fraudulent, expensive and some dangerous claims abound. The public is searching for answers but is often lured by quick fixes and too good to be true results. If you have ever wasted money on diets or products that promised results, but did not deliver, you know this is the case. Arm yourself with credible, science based info, to protect yourself from fads and scams. We hope to give you some of that info here.”

The promise of quick fixes, potions and miracle products can be enticing. Feeling pressure from social or cultural constraints can also make people vulnerable or desperate to try anything. Not to mention – regular diet and exercise can be hard! It requires time and commitment, even if it doesn’t line up with big events, summer bikini season or vacations.


  1. Can exercise, eating certain foods (like spices, coconut oil, putting butter in your coffee) or eating at certain times of day actually change or “boost” your metabolism?


RF: “There are factors that effect your metabolism or how much energy your body uses at rest. These include, importantly, how much muscle mass you have. Muscle burns more energy than fat. Other factors are related to this body composition effect in metabolism include age (because we typically lose muscle with age and hormonal changes), gender (men tend to have more muscle) and body size. Therefore, the best way to increase your metabolism is to regularly engage in muscle building physical activity.


Genetics, hormones and even the rate at which someone loses weight can also play a part in an individual’s metabolism. There’s no such thing as a 30 day workout routine or recipe that can “kick start” or “boost” your metabolism drastically. Putting hot pepper in your smoothie won’t make you miraculously melt fat or bump your resting metabolic rate through the ceiling. If it did, anyone who ever ate a pepper would notice the change. Expect slight, gradual changes in metabolism, especially with regular steady exercise over time rather than rapid means.


Nutrient timing can make a difference for specific athlete populations. A body builder will have different nutrition than an endurance athlete, and the way their bodies use these nutrients vary. Timing out certain foods for people mainly dieting for weight / fat loss (like post-workout, and balanced meals throughout the day) can make a difference but it doesn’t need to be as complicated as some suggest (intermittent fasting or not eating after 8pm for example, won’t matter if the total number of calories in the day stays the same). Those that have success from these diets have more to do with creating a caloric deficit. If you prefer to follow intermittent fasting or eating before 8pm, then there’s no problem with that. Just don’t expect it to change your body composition. Instead, focus more on a caloric deficit calculated from your total daily energy expenditure (TDEE) that isn’t too extreme.


  1. Does tea or juice cleanses “detox” your body?


RF: Humans are well designed, with livers, kidneys and a digestive system designed to rid the body of waste. There is no need to detox diet, cleanse or fast. However, these approaches are popular with celebrities and many think they are a way to get a Hollywood body. While some use teas or juicing to jump start a new plan beware that more than a day or two can cause nutrient deficiencies. Also, limiting your intake to a special tea or juice for prolonged periods is a very low calorie intake, which can backfire a weight loss plan by slowing your metabolism. The opposite of what you are aiming for!


Additionally, the weight lost from consuming too few calories and not enough protein (like only drinking juice) is an overall loss of mass. This includes fat and muscle mass. Strength training can increase muscle mass, but you also need balanced macronutrients in the diet to keep that hard earned muscle. For a goal of fat loss, juicing isn’t the safest way. If you think you have “toxins”, trust your liver and kidneys! Then consider a balanced diet of whole foods, limiting processed goods. If you’re not sure what that is, think of foods that were grown or farmed, rather than packaged.


  1. Does eliminating sugar or a macronutrient like carbs or fats help you lose weight?


RF; Consistently eating less calories than your body uses will lead to weight loss. But to do so, you need a consistent 500 calorie per day deficit to lose 1 pound a week. Cutting out carbs has become a popular approach. If you eliminate several food groups, like grains, pasta, starchy vegetables, fruits and baked goods, all carb-containing foods, you will lose weight. The downside is that you will have missing important nutrients [and fiber], and it may be difficult to have such a restricted eating pattern in the long term.


A more moderate approach that includes nutrient dense carbs ( think a bowl of oatmeal vs a donut) is advised. A word about sugar; specifically added sugars like table sugar or corn syrup. We eat way too much- more than 100 pounds a year per person. These sugars do not add essential nutrients just empty calories. These sugars are everywhere in our food supply and have many negative health effects contributing to obesity and chronic diseases. The best defense here is cut out sugary drinks and desserts and highly processed foods.


The low-carb trend has been around for years, it just shows up with a new name. From sugar busters, to Atkins, to some Paleo approaches and now the current Keto diets, low-carb types can have other health risks if you’re not careful. These are not for everyone and could potentially impact your relationship with food, conditioning you to be fearful or avoidant of many foods. This can lead to binges, feelings of guilt or shame, or isolation from social events. Flexible dieting or the popular “if it fits your macros” is one way to consider preventing this from happening. Rather than eliminating all sugary or processed foods for all of eternity, consider regularly planning the treats you love in a balanced diet, just don’t over do it! If you want a donut, one way to plan it in is to indulge right after a hard workout, then stick to whole foods the rest of the day. This can help maintain a healthy outlook and prevent fear, avoidance and binges.


  1. What’s gluten and should it be avoided?


RF: “Gluten is a protein found in wheat, barley and rye. If you are in the 1% of the population who has celiac sprue, a genetic autoimmune disease, you must eliminate gluten from your diet. 

However, gluten free diet has become a mainstream fad with a proliferation of new gluten free food products. Why is gluten free the latest fad? One study showed subjects that ate a gluten free diet had less GI symptoms. He did a second study with greater control and reversed his findings! Gluten intolerance or sensitivity have been largely debunked.”


This trend is another way I see people becoming fearful of food. If any food causes GI upset or intolerances, then it’s probably a good idea to stay away from it. If you’re hoping to lose weight going gluten-free, then you’ll likely be disappointed. Those that do lose weight from this dietary change is more likely a result of increased nutrient dense and decreased calorie dense foods.


  1. Does muscle weigh more than fat?


Nope. 1lb of fat weighs the same as 1lb of muscle. The difference is in the amount of space fat takes up compared to muscle. Muscle doesn’t take up as much space. This brings up another point; body weight is only one indicator of health and there are other useful ways of calculating progress like tape measurements, body fat testing and photos to track your progress. These can be beneficial for people triggered by the scale.


Finally, I wanted to ask about recommendations.

Throughout your career, you’ve seen plenty diets and fads become popular. This can be overwhelming and confusing for someone just starting out. What would you tell someone looking to take the first step?

RF: “A healthy eating plan is one that is balanced, and that you can stick with. Diets, especially those that are extremely limiting, can’t easily be maintained in the long term and may make you miss out on key nutrients. Also, extreme diets that cause you to lose weight quickly, and then gain it back when you stop, are detrimental to both weight control and health. Focusing on a few latest and greatest magic substances found in foods, touted to be the answer to everything that ails you is not a recipe for health. However, studies of populations around the world have shown relationships with lifestyle including physical activity and eating habits with health and longevity. The Mediterranean diet, which is high in fruits and vegetables, lean meat and fish, whole grains, beans and nuts , with eggs and dairy in moderation and low in sugar and red meat has shown this association. These countries also have a much less reliance on processed foods and prepare simple dishes using real food, and seasoned with olive oil, herbs and spices. I agree with the words of Michael Pollan the best advice is to ‘eat food , not too much, mostly plants’.” 


Lastly, I kept GMO’s and probiotics out of the conversation, but I think it is worth briefly mentioning. There’s a lot of discussion on GMO’s and probiotics lately, and researchers are turning attention to these topics. Right now there simply isn’t enough information to make strong recommendations but in time, there may be some useful evidence to consider.


In summary, I like James Fell’s basic guidelines to keep in mind:


“Calories matter to weight loss.

Selling shakes doesn’t make  you a ‘coach’

Overpriced saran wrap doesn’t melt belly fat.

Most supplements create expensive pee.

Your liver and kidneys do all the detoxing you need.

Exercise is not a punishment to be endured.

Choose a diet you can stick to.

The models in those photos don’t look like that either.

Organic is a marketing gimmick.

Cardio and weights are different. There is no ‘better’

Sugar is neither toxic nor addictive.

Shaming doesn’t help people lose weight.

Most people can handle gluten just fine.

Oils are not essential.”