I love nutrition, but I really hate the way it tends to be practiced.
Many dietitians are NOT basing their nutrition advice on the latest science (1).
The general guidelines are completely outdated. They have barely changed in the past few decades, even though nutrition science has advanced greatly.
I’ve personally stopped getting into arguments about nutrition online, because it is time consuming and frustrating.
But I know that a lot of people do get into these arguments often, so I’ve decided to write an article to give people some “weapons” to win these arguments easily.
By far the best way to win an argument about nutrition is to have a link to a good scientific study. Nutrition is science, after all, although it often tends to resemble religion or politics.
If you ever find yourself in an argument with an outdated nutrition professional, vegan or low-fat zealot, then feel free to use the answers and studies listed below.
Make sure to bookmark this page if you tend to get in these types of arguments often!
Disclaimer: Many nutritionists are good, highly intelligent, competent people. But unfortunately… the ones that are the most prominent in the media usually spew the same anti-fat, high-grain nonsense that got us into this public health disaster.
Nutritionist Says: “The Best Diet is a Low-Fat Diet, With Carbs at 50-60% of Calories”
Answer: The low-fat diet has been put to the test in several huge randomized controlled trials. It does not cause any weight loss over a period of 7.5 years and it has literally no effect on heart disease or cancer.
The low-fat diet is a huge failure. All the major studies show that it doesn’t work.
- Howard BV, et al. Low-fat dietary pattern and weight change over 7 years: the Women’s Health Initiative Dietary Modification Trial. Journal of the American Medical Association, 2006.
- Howard BV, et al. Low-Fat Dietary Pattern and Risk of Cardiovascular Disease. Journal of the American Medical Association, 2006.
- Multiple Risk Factor Intervention Trial: Risk Factor Changes and Mortality Results. Journal of the American Medical Association, 1982.
More: Show them this article.
Nutritionist Says: “Sugar is Bad For You, But Only Because it is Empty Calories”
Answer: The harmful effects of sugar go way beyond empty calories. When consumed in excess, it can lead to severe harmful effects on metabolism and cause insulin resistance, fatty liver disease and various other metabolic disorders.
The studies show that in the long run, a high consumption of sugar is strongly associated with the risk of obesity, type II diabetes, heart disease and even cancer.
- Stanhope KL, et al. Consuming fructose-sweetened, not glucose-sweetened, beverages increases visceral adiposity and lipids and decreases insulin sensitivity in overweight/obese humans. Journal of Clinical Investigation, 2009.
- Stanhope KL, et al. Adverse metabolic effects of dietary fructose: results from the recent epidemiological, clinical, and mechanistic studies. Current Opinion in Lipidology, 2013.
- Ludwig DS, et al. Relation between consumption of sugar-sweetened drinks and childhood obesity: a prospective, observational analysis. The Lancet, 2001.
- Schulze MB, et al. Sugar-Sweetened Beverages, Weight Gain, and Incidence of Type 2 Diabetes in Young and Middle-Aged Women. Journal of the American Medical Association, 2004.
- Bostick RM, et al. Sweetened beverage consumption and risk of coronary heart disease in women. Cancer Causes & Control, 1994.
- Fung TT, et al. Sugar, meat, and fat intake, and non-dietary risk factors for colon cancer incidence in Iowa women. The American Journal of Clinical Nutrition, 2009.
More: Even more studies here.
Nutritionist Says: “Eggs Raise Cholesterol and Lead to Heart Disease”
Answer: The cholesterol in eggs does not raise the “bad” cholesterol in the blood. It raises HDL (the “good”) cholesterol and eggs actually improve the blood lipid profile.
The studies show that egg consumption is not associated with heart disease. Whole eggs are among the most nutritious foods on the planet.
- Rong Y, et al. Egg consumption and risk of coronary heart disease and stroke: dose-response meta-analysis of prospective cohort studies. British Medical Journal, 2013.
- Fernandez ML. Dietary cholesterol provided by eggs and plasma lipoproteins in healthy populations. Current Opinion in Clinical Nutrition & Metabolic Care, 2006.
- Blesso CN, et al. Whole egg consumption improves lipoprotein profiles and insulin sensitivity to a greater extent than yolk-free egg substitute in individuals with metabolic syndrome. Metabolism, 2013.
More: Details on the health benefits of eggs and more studies here.
Nutritionist Says: “Protein is Bad For Your Kidneys”
Answer: It is often claimed that a high protein intake can cause harm to the kidneys, but this is false. Even though it is important for people with pre-existing kidney disease to reduce protein, the same is not true for people with healthy kidneys.
The studies show that a high protein intake has no detrimental effects of kidney function in healthy people, not even in bodybuilders that eat massive amounts of protein.
- Manninen AH. High-Protein Weight Loss Diets and Purported Adverse Effects: Where is the Evidence? Journal of the International Society of Sports Nutrition, 2004.
- Martin WM, et al. Dietary protein intake and renal function. Nutrition & Metabolism, 2005.
Nutritionist Says: “Saturated Fat Raises Cholesterol and Causes Heart Disease”
Answer: This is a myth. Saturated fat raises HDL (the “good”) cholesterol and changes the LDL from small, dense to Large LDL, which is benign and doesn’t increase the risk of heart disease.
This has been intensively studied in the past few decades and the studies consistently show that saturated fat is not in any way related to the risk of heart disease.
- Siri-Tarino PW, et al. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. The American Journal of Clinical Nutrition, 2010.
- Mente A, et al. A systematic review of the evidence supporting a causal link between dietary factors and coronary heart disease. Archives of Internal Medicine, 2009.
- Dreon DM, et al. Change in dietary saturated fat intake is correlated with change in mass of large low-density-lipoprotein particles in men. The American Journal of Clinical Nutrition, 1998.
Nutritionist Says: “Low Carb Diets Are Unhealthy”
Answer: This is simply not true. Since the year 2002, low-carb diets have been studied extensively and over 20 randomized controlled trials have been conducted.
They consistently lead to much better health outcomes than the typical low-fat diet. They cause more weight loss and improve all major risk factors for disease, including triglycerides, HDL and blood sugar levels.
- Westman EC, et al. Low-carbohydrate nutrition and metabolism. American Journal of Clinical Nutrition, 2007.
- Hession M, et al. Systematic review of randomized controlled trials of low-carbohydrate vs. low-fat/low-calorie diets in the management of obesity and its comorbidities. Obesity Reviews, 2008.
- Santos F, et al. Systematic review and meta-analysis of clinical trials of the effects of low carbohydrate diets on cardiovascular risk factors. Obesity Reviews, 2012.
More: Many more studies and a thorough review of the science here.
Nutritionist Says: “Red Meat is Unhealthy and Should Only be Eaten in Moderation”
Answer: It is true that consumption of processed meat is associated with an increased risk of many disease, but the same is not true for unprocessed red meat.
Unprocessed red meat is harmless, although it may form harmful compounds if it is overcooked. The answer is not to avoid red meat, but to make sure not to burn it.
The association between unprocessed red meat and cancer is highly exaggerated, large review studies show that the effect is very weak in men and nonexistent in women.
- Micha R, et al. Red and processed meat consumption and risk of incident coronary heart disease, stroke, and diabetes mellitus: a systematic review and meta-analysis. Circulation, 2010.
- Rohrmann S, et al. Meat consumption and mortality – results from the European Prospective Investigation into Cancer and Nutrition. BMC Medicine, 2013.
- Alexander DD, et al. Meta-analysis of prospective studies of red meat consumption and colorectal cancer. European Journal of Cancer Prevention, 2011.
- Alexander DD, et al. Red meat and colorectal cancer: a critical summary of prospective epidemiologic studies. Obesity Reviews, 2011.
More: More studies on red meat here.
Nutritionist Says: “Protein is Bad For Your Bones and Causes Osteoporosis”
Answer: Although it is true that protein can cause calcium loss from the bones in the short term, this effect does not persist in the long term.
In fact, the studies consistently show that protein actually improves bone health in the long run, NOT the other way around. Therefore, the terrible advice to keep protein low is likely to increase the risk of osteoporosis.
- Kerstetter JE, et al. Dietary protein and skeletal health: a review of recent human research. Current Opinion in Lipidology, 2011.
- Bonjour JP. Dietary protein: an essential nutrient for bone health. The Journal of the American College of Nutrition, 2005.
- Munger RG, et al. Prospective study of dietary protein intake and risk of hip fracture in postmenopausal women. The American Journal of Clinical Nutrition, 1999.
Nutritionist Says: “People Should Cut Back on Sodium”
Answer: Even though sodium restriction can lower blood pressure, it does not appear to reduce the risk of heart disease or death.
Some studies even show that if you restrict sodium too much, that it can increase some risk factors for disease.
There is no science behind the 1500-2300 mg per day recommendation and people that are healthy can eat “normal” amounts of sodium without any harm.
- Taylor RS, et al. Reduced dietary salt for the prevention of cardiovascular disease. Cochrane Database of Systematic Reviews, 2011.
- Jurgens G, et al. Effects of low sodium diet versus high sodium diet on blood pressure, renin, aldosterone, catecholamines, cholesterols, and triglyceride. Cochrane Database of Systematic Reviews, 2003.
- Garg R, et al. Low-salt diet increases insulin resistance in healthy subjects. Metabolism, 2011.
Nutritionist Says: “Polyunsaturated Fats Lower Cholesterol and Reduce Heart Disease Risk”
Answer: There are two types of polyunsaturated fats, Omega-3 and Omega-6. It is true that Omega-3s reduce the risk of heart disease, but the same is not true for the Omega-6s.
Even though the Omega-6s (soybean oil, corn oil, etc.) can lower cholesterol, the studies show that they actually increase the risk of heart disease.
Therefore, the horrible advice to increase polyunsaturated fat, without regards to the type, is probably contributing to heart disease instead of preventing it.
- Ramsden CE, et al. Use of dietary linoleic acid for secondary prevention of coronary heart disease and death. British Medical Journal, 2013.
- Lands WE, et al. Dietary fat and health: the evidence and the politics of prevention: careful use of dietary fats can improve life and prevent disease. Annals of the New York Academy of Sciences, 2005.
- Ramsden CE, et al. n-6 fatty acid-specific and mixed polyunsaturate dietary interventions have different effects on CHD risk: a meta-analysis of randomised controlled trials. British Journal of Nutrition, 2010.
More: Many more studies on vegetable oils here.
Nutritionist Says: “People Should Choose Low-Fat Dairy Products to Reduce Calories and Saturated Fat”
Answer: There is no evidence that people benefit from choosing low-fat instead of full-fat dairy products. Plus low-fat dairy is usually high in sugar, which makes this misguided advice seriously questionable.
Full-fat dairy (especially from grass-fed cows) contains many important nutrients like Vitamin K2 and butyrate, which are very scarce in the diet.
High fat dairy products are actually associated with a lower risk of obesity. In countries where cows are largely grass-fed, people who eat the most high fat dairy products have a drastically reduced risk of heart disease.
- Kratz M, et al. The relationship between high-fat dairy consumption and obesity, cardiovascular, and metabolic disease. European Journal of Nutrition, 2013.
- Bonthius M, et al. Dairy consumption and patterns of mortality of Australian adults. European Journal of Clinical Nutrition, 2010.
- Smit, et al. Conjugated linoleic acid in adipose tissue and risk of myocardial infarction. The American Journal of Clinical Nutrition, 2010.
Nutritionist Says: “Weight Loss is All About Calories in and Calories Out”
Answer: This is completely false, different calorie sources go through different metabolic pathways in the body and have varying effects on hunger, hormones and the brain.
Also, let’s not forget that health is about way more than just weight. Certain calorie sources (added sugar, vegetable oils) can cause harmful effects on metabolism that have nothing to do with their caloric value.
- Feinman RD, et al.“A calorie is a calorie” violates the second law of thermodynamics. Nutrition Journal, 2004.
- Johnston CS, et al. Postprandial thermogenesis is increased 100% on a high-protein, low-fat diet versus a high-carbohydrate, low-fat diet in healthy, young women. The Journal of the American College of Nutrition, 2002.
- Veldhorst MA, et al. Presence or absence of carbohydrates and the proportion of fat in a high-protein diet affect appetite suppression but not energy expenditure in normal-weight human subjects fed in energy balance. British Journal of Nutrition, 2010.
More: Many more studies on the calorie myth here.
Nutritionist Says: “It is Best to Eat Many Small Meals Throughout The Day”
Answer: It is a myth that it is best to eat many, small meals instead of several bigger meals. The studies show that it doesn’t have any effect on health or body weight.
- Bellisle F, et al. Meal frequency and energy balance. British Journal of Nutrition, 1997.
- Cameron JD, et al. Increased meal frequency does not promote greater weight loss in subjects who were prescribed an 8-week equi-energetic energy-restricted diet. British Journal of Nutrition, 2010.
More: A thorough debunking of this myth here.
Nutritionist Says: “Fat Makes You Fat”
Answer: Even though fat has more calories per gram than carbs and protein, it is not any more fattening. Eating foods that are naturally high in fat tends to reduce the appetite.
The studies consistently show that diets that are high in fat (but low in carbs) lead to much more weight loss than diets that are low in fat.
- Brehm BJ, et al. A randomized trial comparing a very low carbohydrate diet and a calorie-restricted low fat diet on body weight and cardiovascular risk factors in healthy women. The Journal of Clinical Endocrinology & Metabolism, 2003.
- Yancy WS, et al. A low-carbohydrate, ketogenic diet versus a low-fat diet to treat obesity and hyperlipidemia: a randomized, controlled trial. Annals of Internal Medicine, 2004.
- Westman EC, et al. The effect of a low-carbohydrate, ketogenic diet versus a low-glycemic index diet on glycemic control in type 2 diabetes mellitus. Nutrition & Metabolism, 2008.
Are there any other ridiculous myths you would like me to cover? Leave a comment below and I’ll see if I can add them to the list.
It would be awesome if this article could become a “weapon” for us all to change the world, one nutritionist at a time.