In episode 5, weight-loss nutritionist and founder of SammieNehmi Nutrition & Wellness LLC, Sammie Nehmi, discussed the dangers of fad diets and how falling for them in the past has led to her own digestive consequences. Additionally, Sammie and Sarah Tannen, Registered Dietitian Nutritionist and founder of Nutrition with Sarah, both explained the importance of eating a balanced diet for optimal health, weight loss, and weight management. I wanted to dive a bit deeper into the science behind weight loss and why fad diets do not work.
Let’s start with some definitions.
- The energy balance equation is energy intake = energy expenditure +/- (fat intake – fat oxidation) (Summerfield & Ellis, 2016, p. 101).
- The resting metabolic rate (RMR) is the amount of energy used when people are awake and have not exercised or eaten recently (McMurray et al., 2014, p. 1353). RMR accounts for the majority of energy expended and is impacted by body size (Summerfield & Ellis, 2016, pp. 92-107).
- The thermic effect of food (TEF) is when heat is produced after eating (Summerfield & Ellis, 2016, p. 111). The amount of food, the frequency of food eaten, and the type of food eaten impact the TEF (Summerfield & Ellis, 2016, p. 113). It is important for people to eat a balanced diet with the correct amount of food for people to increase their TEF and manage weight (Summerfield & Ellis, 2016, p. 113).
- The thermic effect of exercise (TEE) is when heat is produced from exercise (Summerfield & Ellis, 2016, p. 115). The amount of energy expended depends on body size, type of activity, and duration and intensity of activity (Summerfield & Ellis, 2016, p. 115).
- Energy can also be expended when a person is not exercising through non-exercise activity thermogenesis (NEAT). NEAT is impacted by how much a person stands and moves around at their job, during leisure activities, and while using devices (Summerfield & Ellis, 2016, p. 117).
- Metabolic adaptation occurs when a person loses a substantial amount of fat mass and fat-free mass (FFM), and the body adjusts to this change. When metabolic adaptation happens, a person’s metabolic rate slows and less energy is used because the body doesn’t want the person to continue to lose mass (Johannsen et al., 2012, p. 2489).
Okay, so why did I just give you all of these definitions?
Because our RMR, TEF, TEE, NEAT, and metabolic adaptation all impact our ability to lose weight.
Metabolic adaptation can play a large role in weight loss. It is impacted by how much and how fast FMM was lost; the amount of food consumed; amount of exercise completed; amount of energy expended at work and during leisure activities; and the person’s environment, genetics, thyroid hormone production, body size, age, and gender (Johannsen et al., 2012, pp. 2492-2493; von Leoffelholz & Birkenfeld, 2018).
So where do fad diets come into play?
When a person loses FFM extremely quickly due to a fad diet, a person’s metabolic rate slows, and metabolic adaptation occurs. If a person has a slower metabolic rate, they will be more likely to regain weight if they are not continuing to manage caloric intake and exercise frequently (Johannsen et al., 2012, p. 2489). Most people who engage in fad diets are looking for a quick fix and only intend on engaging in this very low calorie, low-fat, or low-carbohydrate diet for a short amount of time. Once they go back to working out less frequently and eating more calories, their slowed metabolic rate could cause them to expend less energy and gain weight.
Therefore, instead of buying into a fad diet, crazy exercise plan, or quick fix, there are a few actions someone could take to lose weight and prevent metabolic adaptation.
- Engage in at least 150 minutes of exercise per week and partake in muscle-strengthening activities at least two times per week (American Heart Association, 2018).
- Stay active at work and during leisure activities. Small ways that people could increase activity are by standing at work instead of sitting and choosing leisure activities that involve movement like cooking or gardening (von Leoffelholz & Birkenfeld, 2018).
- Eat a balanced diet full of healthy proteins, carbohydrates, and fats and decrease your intake of foods that contain empty calories like soda and candy.
- Work with a nutritionist, dietitian, or other health practitioner who can help you create a healthy diet and exercise plan.
If you are interested in working with Sammie or Sarah, you can find more information about their programs on their websites below:
- Sammie: SammieNehmi Nutrition WL2 program (squarespace.com)
- Sarah: Nutrition and Wellness | Nutrition With Sarah
Additionally, if you would like to start eating a more balanced and healthy diet today, check out my 7 Day Meal Plan. My meal plan is rooted in research to help you consume adequate amounts of macro- and micronutrients.
References
American Heart Association recommendations for physical activity in adults and kids. www.heart.org. (2018, April 18). Retrieved January 26, 2022, from https://www.heart.org/en/healthy-living/fitness/fitness-basics/aha-recs-for-physical-activity-in-adults
Johannsen, D. L., Knuth, N. D., Huizenga, R., Rood, J. C., Ravussin, E., & Hall, K. D. (2012). Metabolic slowing with massive weight loss despite preservation of fat-free mass. Obstetrical & Gynecological Survey, 67(11), 2489–2496. https://doi.org/10.1097/01.ogx.0000423189.40994.eb
McMurray, R., Soares, J., Caspersen, C. J., & McCurdy, T. (2014). Examining variations of resting metabolic rate of adults. Medicine & Science in Sports & Exercise, 46(7), 1352–1358. https://doi.org/10.1249/mss.0000000000000232
Summerfield, L. M., & Ellis, S. K. (2016). Chapter 4: Energy Metabolism. In Nutrition, exercise, and behavior: An integrated approach to weight management (3rd ed., p. 108). Wadsworth Cengage Learning.
von Loeffelholz C, Birkenfeld A. The Role of Non-exercise Activity Thermogenesis in Human Obesity. [Updated 2018 Apr 9]. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK279077
