Why is losing weight so hard — and keeping it off even harder? Mechanisms in the brain can sabotage efforts to eat less and avoid unhealthy foods, according to research. However, the following strategies may help your body win its battle with your brain to control weight, which is essential for overall health and limiting stress on aching joints.
Recent research suggests that a dip in activity in the brain’s prefrontal cortex may make you crave high-calorie foods. In an experiment, neuroscientist Cassandra Lowe, Ph.D. of the University of Western Ontario, and colleagues let volunteers eat as much snack food as they wished. At a later session, a device was used to quiet prefrontal cortex activity in volunteers. When
offered snacks again, their appetite for chocolate and potato chips spiked, while they shunned low-calorie snacks. (Studies also show that weight gain causes structural changes in the brain that further weaken resolve when choosing between a cheeseburger and a salad, creating a vicious cycle.)
Eating treats like pizza and cookies also activate “reward centers” in the brain, making you desire them more. “But we’re not purely driven by rewards,” says Lowe. “We have other processes that allow control over our behavior.”
STOP THE CYCLE
Exercise boosts activity in the prefrontal cortex, and Lowe showed in another study that volunteers’ appetites for unhealthy snacks decreased after brisk walking. She adds that practicing mindfulness meditation can help you stay focused on choosing healthy foods.
When you eat a meal, fat cells produce the hormone leptin, which travels to the hypothalamus in the brain.
When you have consumed enough food to keep your body functioning, leptin delivers a signal to the hypothalamus: “Stop eating, you’re full.” However, brain cells may become less responsive to these signals, which can lead to overeating and weight gain, says endocrinologist Benjamin O’Donnell, MD, of The Ohio State University Wexner Medical Center, in Columbus.
“You don’t feel the usual signals of satiety if you’re eating rapidly,” says Dr. O’Donnell. He suggests keeping a 30-second hourglass by your plate. When you take a bite, flip the timer and let it run out before you take another bite. Over time, you’ll learn the difference between feeling satisfied and stuffed, he says.
When you polish offa pint of Chunky Monkey ice cream at the end of a stressful day, blame your brain’s amygdala. Chronic stress causes it to signal the adrenal glands to churn out cortisol, which (among other roles) increases appetite, usually for high-calorie comfort foods. Studies link persistent stress to obesity, especially belly fat.
Find a way to relax – whether it’s meditation, yoga, prayer or fly fishing – and stick with it.