Possible Problems with Fasting and Autophagy

November 19th, 2021 | Posted in Info

If you’ve read the blog post on The Protective Effects of Autophagy you’ll know that evidence is mounting for the benefits of stimulating this mechanism in the body. However, as with all things moderation is the key. Too much autophagy can become a problem. It’s all about balance: Fasting is a time for cell cleansing and healing, whereas feasting is a time for growth, rebuilding, and reproduction.

When practising intermittent fasting the goal is not necessarily to eat less overall, just to eat less often.

Prolonged calorie restriction is not recommended as it may have negative consequences including:

Adrenal stress – prolonged calorie restriction can lead to increased cortisol production which may lead to sleep problems, fatigue, slow recovery, muscle wasting and adrenal fatigue.

Sex Hormone imbalances – any type of fasting or prolonged calorie restriction gives the body the message that it is not a good time to reproduce. This leads to the decline of sex hormones and potentially infertility and other hormone related problems.

Female bodies are particularly sensitive to calorie restriction and restrictive diets so care should be taken not to overdo any kind of fasting. The goal is not necessarily to eat less overall but to eat less often and to go longer without food. If you find your dietary changes are affecting your menstrual cycle or fertility it may be that you need to eat more calories and more often.

If you are pregnant, planning to get pregnant, or breastfeeding this is unlikely to be the best time to start intermittent fasting.

Menstrual irregularities – any kind of calorie restriction or fasting may lead to less regular menstrual cycles or amenorrhoea, when periods stop completely. This has negative consequences for fertility and bone health.

Reduced muscle size — long-term intermittent fasting can lead to loss of muscle.

Lower basal metabolic rate (BMR) — BMR is the amount of calories we use when we are at rest. BMR might be reduced during longer bouts of intermittent fasting as the body tries to preserve energy. Longer periods of fasting lock the body into a lower calorie spending state (starvation state), which may make weight gain more likely and weight loss more difficult.

Thyroid problems – the thyroid gland plays a key role in metabolism and may be affected by fasting.

As with everything intermittent fasting may benefit some, and not others. More research is needed to establish why some people benefit, while others don’t.


Talk to your doctor or health care provider before embarking on any fasting regime.