We know that there are many harmful and surprising effects of dieting that can occur; specifically when engaging in weight cycling/”yo-yo dieting”. However, we have yet to look closely at what ACTUALLY happens to our bodies when we decide to go on a new diet. 

 

Generally, after dieting the majority of the weight lost is gained back within 3 – 5 years. So, what is actually going on here? Why does this happen? Most research points to our body’s biological response to weight loss and trying to maintain homeostasis in the body. Our body weight is affected by biological, environmental, and behavioral pressures, which are all influenced by our genetics. Hence why bodies come in all shapes and sizes because no two humans are genetically identical. The body is continuously trying to keep these three components balanced and when one becomes unbalanced it is the biological component that tries to re-establish balance to prevent severe weight loss or gain. When the body experiences weight loss, there is a metabolic drive to regain lost weight. Homeostasis works in the same way as when you become either too hot or too cold, your body will work to control your temperature to a safe number.

 

Hormones:

Initially, when your body experiences energy deficiency there is a drop in leptin levels in the blood. Leptin is a hormone in the body that helps to control appetite. When this hormone becomes low, individuals will begin to feel more hungry and experience intense cravings. This hormone also signals to the brain that you need to conserve energy as the body is starving.

 

In the Brain:

The hypothalamus has been traditionally considered the homeostatic region in the brain, one of its roles being to help control weight. During periods of energy deficits which is normally the case with dieting, changes in the hypothalamus occur which can induce an anabolic state. Eventually, your metabolism will start to slow down so you can conserve energy for your body which is your brain’s response to starvation (dieting) as your body does not know the difference between the two. 

The hypothalamus’s reaction to energy depletion also results in reduced sensitivity to fullness cues which can result in a higher intake of food due to increased appetite. 

 

Metabolism:

Metabolism can be defined as “the series of chemical reactions in a living organism that create and break down energy necessary for life” (Harvard Health, 2021). There are three reactions that involve the metabolism: 

• Basal or Resting Metabolic Rate (BMR/RMR): amount of energy/calories your body burns to keep you alive regardless of if you are awake or asleep. Your body still uses energy to keep you alive.
• Thermic Effect of Food (TEF): calories/energy you burn digesting food.
• Non-Exercise Activity Thermogenesis (NEAT): calories/energy your body burns through activities of daily living.

(Younkin, 2018)

As a result of less food being consumed, less energy is needed for digestion and absorption of food therefore your metabolism will begin to slow down to conserve energy. 

 

Combine increased appetite, loss of fullness/satiation, and decreased metabolism and you have the perfect recipe for weight regain.

 

As you can see, dieting time and time again is a recipe for metabolic madness and overall does more harm than good as it puts your body through additional unnecessary stress. 

 

Are you ready to find Food Ease and bring internal peace back to your body again? The dietitians at Food Ease Co. can help you to make peace with food through intuitive eating.

 

 

 

References:

Harvard Health. (2021, October 6). Does metabolism matter in weight loss? https://www.health.harvard.edu/diet-and-weight-loss/does-metabolism-matter-in-weight-loss

MacLean, P. S., Bergouignan, A., Cornier, M. A., & 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), R581–R600. https://doi.org/10.1152/ajpregu.00755.2010

Younkin, M. L. S. (2018, May 22). Can losing weight slow your metabolism? EatingWell. https://www.eatingwell.com/article/290811/can-losing-weight-slow-your-metabolism/