Everybody knows that weight-related productivity and health issues are big concerns for modern companies, but losing weight is hard. Like, count-the-needles-on-a-pine-tree hard. And there's a good reason for that. Your body has a built-in mechanism that deliberately tries to keep your weight steady, so if you drop how many calories you consume, your body slows down how fast it burns through fuel to conserve energy and keep you safe. Researchers have figured out exactly how control of this internal caloric "thermostat" works in the brain, according to a new study of mice published in the open access journal eLife.

What the researchers did

Researchers implanted mice with probes so they easily could measure the rodents' body temperature and, therefore, get a measurement of how much energy the mice were using when exposed to different amounts of food. Then they put the mice in special chambers specifically designed to measure energy expenditure through factors like oxygen consumption.

Thus set up to look at the energy and food the mice used, researchers homed in on a region of the brain called the hypothalamus, which controls metabolic and autonomic nervous system activities, among other roles. Within the hypothalamus are agouti-related neuropeptide (AGRP) neurons. The researchers were able to manipulate these cells to turn on or off.

The results of the manipulations suggest that, when AGRP cells are active, we get hungry and want to chow down. But if you don't eat, the cells limit how many calories you burn through, preserving energy to protect you. When you finally eat again, the action of the AGRP neurons gets interrupted, and you start cruising through more calories. Researchers were able to identify the precise mechanism by which AGRP cells determine available energy and make calorie-burn adjustments.

Exercise and slightly reduced calories is best, no starvation diets required

Dr. Luke Burke, lead author on the AGRP cell study, says he is hopeful that the new research will help professionals design new weight loss and overeating therapies. But until those options hit the market, if you want to shed pounds over the long haul, don't just massively cut back on what's on your plate. Instead, as Burke recommends, moderately cut back on your calories and add in some exercise. As Harvard Health Publications explains, regular exercise actually helps elevate the amount of energy you burn even at rest. Subsequently, it counterbalances the AGRP-cell-based metabolic slowdown you get from reducing calories alone. You'll probably find that the ability to eat a little more through your weight loss plan is much more enjoyable, and as a bonus, exercising can give you a serious mood boost. Talk to your doctor to determine the right daily calorie goal and exercise types for you.