Adaptive thermogenesis is the ability of the body to adjust its metabolic rate in response to changes in energy intake and expenditure. This process is necessary to maintain energy balance and prevent weight gain or loss. However, when adaptive thermogenesis becomes chronic, it can harm your health. For example, in the fitness industry, a chronic calorie deficit of over 700+ calories often happens in the pursuit of weight loss. Doing this for months/ years can lead to a chronic adaptive thermogenesis problem.

When you consume fewer calories than your body needs, adaptive thermogenesis kicks in to help you conserve energy. As a result, your metabolic rate slows down, so you burn fewer calories at rest and during physical activity. Unfortunately, losing and maintaining a healthy weight can be challenging, if not impossible.
Chronic adaptive thermogenesis can also lead to metabolic damage. When your body is in a state of energy deficit for an extended period, it can become resistant to weight loss. This means your body that all calories, good or bad, get reserved to be used for organ function. As a result, your body will be starved of energy to regulate hormones, recover, and work out. Resistance to weight loss can be attributed to those hormonal changes, such as decreased levels of thyroid hormone and leptin, which regulate metabolism and hunger.

Furthermore, chronic adaptive thermogenesis can lead to a decrease in muscle mass. When your body is in a state of energy/excessive calorie deficit, it may break down muscle tissue to use as an energy source. This can lead to decreased muscle mass and increased body fat, leading to decreased physical performance, poor metabolic health, and an increased risk of chronic diseases.

In addition, chronic adaptive thermogenesis can increase appetite and cravings for high-calorie, high-fat foods. This is because your body is trying to conserve energy and is signaling you to eat more to compensate for the energy deficit. This can lead to overeating and weight gain, which can further exacerbate metabolic damage and increase the risk of chronic diseases such as adrenal fatigue, type 2 diabetes, heart disease, and certain types of cancer.
In conclusion, while adaptive thermogenesis is necessary to maintain energy balance, chronic adaptive thermogenesis can harm your health. It can lead to metabolic damage, decreased muscle mass, increased appetite and cravings, and an increased risk of chronic diseases. Often adaptive thermogenesis can be avoided by knowing what your body needs for caloric intake for the day. You can learn this by doing a resting metabolic rate test, a DEXA scan, or an in-body scan. If you are struggling with weight loss or maintaining a healthy weight, speaking to a healthcare professional who can provide personalized recommendations based on your needs and health status is crucial.