While the heat wave settles in France in France, a new record was broken this week: 84 metropolitan departments are now affected by the hot weather. A trying climate phenomenon, which also arouses questions about its physiological effects. Among them, a question often comes back: does heat really lose weight?
To see more clearly, we interviewed Dr. Gérald Kierzek, emergency doctor and medical director of True Medical.
Weight loss … misleading
“”We lose weight during a heat wave“, Dr. Kierzek said immediately.”But in a very limited and often misleading way“, he nuances immediately. Because if the thermometer climbs, the figures on the scale can drop-without that reflecting a real loss of mass fat.
Indeed, the body reacts to heat by different mechanisms, including perspiration. When you weigh yourself at the end of the day after sweating a lot, the scale can display one kilo less. But this variation is above all due to a loss of water.
“”By sweating, the body eliminates water and minerals, which can lower the weight on the scale“, Explains the doctor. A only water phenomenon. Rehydration – essential to avoid any risk of dehydration – quickly brings this lost weight. It is therefore not a melting of fat, but a simple temporary imbalance of body fluids.
Less appetite, more impact?
Another well -known effect of heat: loss of appetite. When mercury exceeds 30 ° C, it is common to jump a meal or prefer a fruit to a generous dish. Can this behavior affect our weight more sustainable?
“”By strong heat, some people are less hungry: the body spends less energy to warm up“, observes Dr. Kierzek. A natural drop in metabolism which can result in a reduction in calorie intake, and therefore, potentially, slight weight loss over time.
But it all depends on the eating habits adopted to replace. “”There may be a weight loss effect, in this case, linked to the fact of eating less“, Recognizes the emergencyist.”But not if you replace your meals with ice creams or sugary drinks“He warns.
What to remember
If the heat can induce temporary variations on the scale, these are rarely synonymous with real weight loss. Losing water does not amount to losing fat. And eating less is not always enough to trigger lasting weight loss, especially if nutritional choices are not suitable.
“”The heat does not lose weight in itself. To lose fat, you must maintain a regular calorie deficit over time, with a balanced diet and suitable physical activity“Concludes Dr. Gérald Kierzek.
In summary, if the heat wave influences our food behaviors and our physiological mechanisms, its impact on the weight remains temporary. It is therefore better to remain vigilant, hydrate properly, and not to confuse loss of water and loss of fat.