Studies have shown in terms of long-term weight loss, a combination of diet and exercise may be superior to diet alone. However, research has also shown that no matter the approach, weight regain often time occurs (1). Weight loss is hard. Avoiding weight regain may be even harder. So how do we combat this? First, I think it’s important to understand some of the basic physiology of weight loss.
Weight loss is a simple equation. To maintain weight you need to be in an energy balance. The calories you burn throughout the day must be the same as the calories you consume. To lose weight you need to be in an energy deficit. The amount of calories you burn throughout the day needs to be more than the amount of calories you consume. So how many calories do you burn? Well, I’ll go into how to figure these numbers another time, but today let’s break down what makes up that total caloric expenditure.
Daily Energy Expenditure can be broken down as follows:
Resting Energy Expenditure (REE): Number of calories you need to sustain minimal daily function. Also known as BMR or RMR (no need to go into the differences here)
Thermic Effect of Feeding (TEF): Yes, you are actually burning calories as you eat! It takes fuel to process food and different macros and combinations of foods produce a different thermic effect.
Non-Exercise Activity Thermogenesis (NEAT): Calories expended due to normal daily activity. Walking up stairs, picking up boxes at work, fidgeting, etc.
Thermic Effect of Activity (TEA): Calories expended due to intentional exercise or activity
Mechanisms of Weight Regain Just as it is important to understand the basic principles of weight loss, it’s just as important to understand the mechanisms of weight regain.
With weight loss comes various metabolic and hormonal changes. I have outlined these at a basic level as to not get too “sciency” and to keep this short. Bottom line… there is an overall decrease in total daily energy expenditure (TDEE) due to various metabolic and hormonal changes (3,4).
Changes in hormone responses (Endocrine Adaptations) Ghrelin increases, promoting more hunger and fat storage. Leptin decreases; promoting less satiety. Other various hormonal downshifts or upshifts Metabolic Adaptations A decrease in uncoupling of protons (which basically means less energy expended during the forming of ATP).
Based on the simple equation of calories in, calories out, one might think that cutting calories drastically would be best. However, drastic cuts can lead to losses in muscle mass, slower recovery times and an increased likelihood of weight regain due to the before mentioned metabolic and hormonal changes. It’s important to take a step back and look at the bigger picture. Not just the short term. If this is to be a lifestyle change and if we are doing this for our overall health why put ourselves at a higher risk for weight regain? Instead consider setting yourself up for better success in the long-term, by combating some of these metabolic adaptations and taking it slow. It is not possible to avoid these metabolic adaptations completely, but we can do our best to minimize the changes.
Tip #1: Slow and steady
My philosophy has always been….eat as much as you can while seeing the results you want (0.5-2 lbs of weight loss per week). If you aren’t trying to make weight for a competition, wedding or photoshoot it doesn’t make much sense in rushing the process. Cut your calories slowly and when you stop seeing progress or progress slows adjust from there. You will need to adjust over time eventually by either increasing your expenditure OR decreasing your intake. What once started as a 500 calorie deficit over time becomes less of a deficit.
Tip #2: Refeeds OR diet breaks.
Leaner individuals may especially benefit from this technique, but this can be useful for anybody. Refeeds (sometimes referred to as “cheat days”) are an opportunity for you to take a break psychologically as well as reverse some of the hormonal changes that occur from being in a constant caloric deficit. The research is still out as to the optimal duration refeeds and diet breaks should be in order to minimize or reverse some of these changes, but current findings seem to suggest two days or longer may make the most sense. The recent MATADOR study (5) showed subjects who took two-week diet breaks saw greater weight loss and fat loss results as opposed subjects who dieted 16 continuous weeks. While I love research, it isn’t always the most practical. Do what works best for you and your situation. If you do have a timeline than this approach may not be the best.
Lastly on this topic…avoid utilizing the term “cheat days.” This term ultimately gives people the wrong impression of what a refeed day actually is. It doesn’t mean just throwing down an entire large pizza drenched in ranch and a side of mac and cheese (but if you go there…don’t sweat it). A refeed simply means eating at or around maintenance calorie levels.
Tip #3: Eat Nutrient Dense Foods
As you lose weight, due to some of these hormonal shifts you will most likely at some point feel hungrier. An easy way to deal with this is to eat more nutrient dense foods. These foods, while providing the same amount of calories/energy, will look like more on your plate (which can help psychologically) and will be more satiating.
Tip #4: Track your non-exercise activity (as well as exercise activity)
Activity trackers are all the rage. While studies show these trackers aren’t always the most accurate especially in terms of energy expenditure (6,7), they do have SOME reliability and may be better at tracking steps. Keep in mind as you lose weight NEAT decreases, both due to carrying less overall body weight but also possibly due to less spontaneous activity in general (3). While trackers are not perfect they may help by keeping you more mindful of this by providing you with a general idea of whether or not measurements like daily steps are decreasing over time. As you can see in the image above NEAT makes up more of your caloric expenditure than EAT….Just something to think about.
Wu, T. , Gao, X. , Chen, M. and Van Dam, R. M. (2009), Long‐term effectiveness of diet‐plus‐exercise interventions vs. diet‐only interventions for weight loss: a meta‐analysis. Obesity Reviews, 10: 313-323. doi:1111/j.1467-789X.2008.00547.x Maclean, P. S., Bergouignan, A., Cornier, M., & Jackman, M. R. (2011). Biology’s response to dieting: The impetus for weight regain. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology,301(3). doi:10.1152/ajpregu.00755.2010 Trexler, E., Smith-Ryan, A., & Norton, L. (2014). Metabolic adaptation to weight loss: Implications for the athlete. Journal of the International Society of Sports Nutrition. 11.(7). 10.1186/1550-2783-11-7. Ochner, C. N., Barrios, D. M., Lee, C. D., & Pi-Sunyer, F. X. (2013). Biological mechanisms that promote weight regain following weight loss in obese humans. Physiology & Behavior,120, 106-113. doi:10.1016/j.physbeh.2013.07.009 Byrne, N. M., Sainsbury, A., King, N. A., Hills, A. P., & Wood, R. E. (2017). Intermittent energy restriction improves weight loss efficiency in obese men: The MATADOR study. International Journal of Obesity,42(2), 129-138. doi:10.1038/ijo.2017.206 Evenson, K. R., Goto, M. M., & Furberg, R. D. (2015). Systematic review of the validity and reliability of consumer-wearable activity trackers. International Journal of Behavioral Nutrition and Physical Activity,12(1). doi:10.1186/s12966-015-0314-1 Sasaki, J. E., Hickey, A., Mavilia, M., Tedesco, J., John, D., Keadle, S. K., & Freedson, P. S. (2015). Validation of the Fitbit Wireless Activity Tracker for Prediction of Energy Expenditure. Journal of Physical Activity and Health,12(2), 149-154. doi:10.1123/jpah.2012-0495