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Identifying Nutrition Pseudoscience

By Crystal Hayes, YMCA Dietician


“The human body is a staggeringly complex machine, and our food supply is a staggeringly complex mixture of chemicals… Predicting the outcome of blending these complexities is extremely challenging. Factor in the influence of genetics, food intolerances, allergies, biochemical individuality, and age, and you have a practically unsolvable problem.” Dr. Joe Schwarcz, director of McGill University’s Office for Science and Society


The global health and wellness industry has an estimated value of US$4 trillion. Countless products and services are marketed to improve health, recovery, and/or sports performance. The industry has expanded at an alarming rate, and even with some federal guidelines (e.g. supplements cannot state it cures or treats disease), many products are sold on baseless or exaggerated claims and questionable evidence of safety and efficacy. I have heard of more potentially harmful diets and supplement use from my clients trying to lose weight or find a cure with alternative medicine than I ever imagined before becoming a dietitian. To paint this picture, here is a list of some of the things my clients had tried before on their own that have no research backing the effectiveness for weight loss.   

  • Puree/baby food diet

  • Military diet

  • Detox diet (like other supplements we cannot be sure what is in detox supplements - hint: the liver is our body’s natural detoxifier)

  • Juicing

  • Keto gummies (primarily apple cider vinegar - hint: compare the dose with research studies; you can cook with apple cider vinegar; too much may cause nausea which affects appetite and might be the real reason small short-term research studies showed weight loss)

  • Lipozene (konjac root - hint: just get your fiber from food!)

  • Lemon cayenne drink

  • Water fasting

  • Golo (vitamins, minerals, and herbs with clinical trials on insulin sensitivity - hint: their weight loss program includes a calorie restricted meal plan)

  • Meal replacement shakes

  • Raw food diet

  • Coconut oil 


On the contrary, here are some diets and supplements my clients tried on their own that have mounting research behind them, but the claims about weight loss and improved metabolic profiles are borderline pseudoscience, and many have been adapted into fad diets. 

  • Intermittent fasting (alternate day or time-restricted - hint: short-term studies only, highly variable study design, timing of meals)

  • Ketogenic diet (very low carbohydrate, such as Atkins and South Beach diets - hint: changes metabolism to mimic fasting; overwhelmingly, the literature favors plant protein over animal protein for health benefits)

  • Probiotics (links between the gut microbiome and obesity along with many other health issues - hint: studies have different strains and study participants themselves are diverse so it is hard to generalize; every person’s microbiome is incredibly unique!)

  • Low glycemic diet (better quality carbohydrates - hint: the glycemic index is based on increases in blood sugar, but there are individual responses to the same foods that may differ; some things are not healthier, like how a candy bar and ice cream have a lower glycemic index than rice, potatoes and melon; we don’t typically eat individual foods if we make balanced meals and snacks)

  • Very low calorie diet (<800 calories per day; short-term - hint: this should be medically monitored; results in reduction in RMR and lean body mass, but loss of lean mass does decrease of time)

  • High protein diet (as protein intake increases, the proportion of energy derived from protein also increases - hint: simply choosing higher protein does not attenuate nitrogen losses on a low calorie diet; increased energy intake improves nitrogen balance)


And here are some diets that are evidence-based, but may not be appropriate for an individual depending on their medical and social history, activity level, medications and overall lifestyle.  The current data should shift dietary guidance away from reductionist “one-size-fits-all” nutrient-centric recommendations (eg, “low fat”, “low carb”), to food and dietary pattern-based recommendations that allow for flexibility in the proportion of carbohydrates in the diet, with a focus on quality over quantity and dietary patterns over single nutrients. Adherence is one of the most important determinants of success in any dietary approach.

  • Vegan and vegetarian diets

  • Modified macronutrient diet (low carbohydrate, low fat) 

  • Mediterranean diet 

  • Increased dietary fiber

  • Calorie restriction (Weight Watchers uses points instead of calorie counting; Noom encourages mindful eating and includes coaching)

  • DASH diet


Pseudoscience is a claim for or explanation of an observed phenomenon that’s presented as science despite lacking scientific rigor. I recommend reading this brief article about bogus health claims. Here are some tips to be a smart consumer and look for the best nutrition information:

  • Do not rely on manufacturer claims when determining if a product is safe. Instead, seek out unbiased science-based research. 

  • Consult a medical professional about dietary supplements including vitamins, minerals, herbs and botanicals and see a dietitian for evidenced-based answers to your nutrition questions and personalized recommendations. Dietitians are familiar with the various types of research protocols and how to evaluate the differences among data derived from surveys, epidemiologic studies, or controlled clinical trials.

  • Be aware of the common claims and themes that accompany nutrition misinformation, such as quick fixes, simplistic conclusions from a complex study, twisting data interpretation to support product’s claims, testimonials, single study conclusions, etc.

  • Look for trusted websites such as government or educational institutions.

  • Look at the author’s qualifications and check against multiple sources and perspectives.

  • Look at the funding source for the study to make sure it is unbiased.

It is the role of practitioners to translate the evidence base and personalize it to individual patients. We have decades of research with consistent health benefits shown for the following guidelines: more complex quality carbohydrates, less added sugar, less saturated fat, limiting salt, avoiding excess energy intake, exercising, more minimally processed plant foods than animals, 5-7 servings of fruits and vegetables.


To schedule an appointment with our dietitian, please email Crystal at