Where weight has dropped over the summer, it is worth considering that the loss may be muscle rather than fat, because heat-related loss of appetite and reduced outdoor activity work together.

The scale alone does not say what has gone. Muscle is denser than fat, so the same weight occupies less volume. This is why the body can look slacker even as the number falls.

Protein intake tends to fall in hot weather. People avoid hot cooked dishes in favor of cool drinks and light meals, and daily protein totals end up below normal.

At the same time, more hours indoors with air conditioning mean fewer steps. Muscle is not maintained without use, so when lower intake meets lower activity the rate of loss increases.

The problem is more pronounced in middle age and beyond, since the muscle-building response to the same stimulus declines with age and recovery takes longer.

As autumn begins, restoring both food intake and activity is advised. A sudden increase in exercise raises injury risk, so the adjustment should be gradual.

This article summarizes general health information and does not substitute for individual diagnosis. Where weight change is large or unexplained, medical consultation is appropriate.