Weight loss will be much faster in lean than in obese hunger strikers

EDITOR—Peel's editorial article on hunger strikers draws attention to an area of pathophysiology that few doctors will be familiar with.1 There is an extensive literature on the normal physiological response to fasting and pathological events that may occur during prolonged therapeutic starvation, a treatment for morbid obesity that has largely been abandoned because of lack of long term success and pressure on hospital beds.

When monitoring adverse events, and especially the time to the appearance of such events, it is essential to take into consideration the weight of the starving subjects before the fast. Studies of starvation that colleagues and I have carried out have highlighted important differences in metabolic adaptive responses between subjects who were obese and those who were of normal weight, especially in terms of protein metabolism. 2 3 After just 60 hours of fasting, lean subjects showed active protein breakdown whereas obese subjects did not. In addition, the rate of weight loss was greater in lean than obese subjects, lean subjects having lost 3.9% of their initial body weight after 60 hours whereas obese subjects had lost 2.4%. Peel suggests independent medical monitoring after a weight loss of 10% in lean healthy subjects. This weight loss is likely to be arrived at much sooner in lean than obese subjects: our obese subjects lost only 9.3% of their initial body weight after fasting for two weeks.

Peel is right to warn of the dangers of refeeding. Colleagues and I described one patient who developed recurrent ventricular tachycardia when feeding restarted after total therapeutic starvation. He was successfully resuscitated4 but subsequently developed a moderately severe proximal myopathy, which recovered.5 Doctors caring for people on prolonged hunger strikes or supervising prolonged therapeutic starvation need to be aware of the many dangers of this unusual metabolic situation.