Edited by Kate Findley, The Great Courses Daily
You may associate weight loss with grueling exercise, starvation diets, and general deprivation. Peter M. Vishton, Ph.D., offers a solution that is both more effective and more pleasant.
Why Healthy Snacks Beat Starvation
Eating small, healthy snacks is often proposed as an effective weight loss strategy. But what constitutes a “healthy” snack?
First, it is helpful to understand why snacking is beneficial. Here’s a tip, which cognitive neuroscience and nutritional science both agree on: If you’re hungry, you should eat something; conversely, when you’re not hungry, you should not eat.
This doesn’t sound like rocket science, but let’s unpack those two statements. If you’re hungry, your body is sending you a message that it’s changed from a mode of processing incoming energy to a mode of needing more energy (i.e., food).
Calorie-restricted diets are only a short-term solution. Unless you’re really willing and able to spend all of your waking hours focusing on controlling your eating, you’ll eventually slip.
There’s another problem with ignoring this hunger signal. Leptin and ghrelin influence the hypothalamus, which regulates your internal sense of hunger. These two hormones also influence your body’s metabolism.
Your body seeks to maintain its weight and to store some fat in case there’s a famine at some point in the future. The hunger hormones will actually reduce the rate at which your body burns energy. For example, they can make you feel sluggish, which causes you to move around less.
Too much ghrelin will activate the mechanism that stores energy in fat cells. If you’re feeling hungry, you’ll use fewer of the calories that you eat and store more of them by enlarging fat cells.
The Limits of Exercise
You can fight this process with physical activities such as walking, running, and biking. Unless you go to extremes with that, however, it can prove to be a losing battle. For every mile you run, you burn about 150 calories. Five miles adds up to 750 calories burned.
Sadly, you can eat that back with a couple of slices of pizza or an extra soda or two. In other words, we’re too efficient at acquiring energy from our foods for exercise to work on its own.
Of course, there are great reasons to exercise. Your brain even produces extra new neurons if you exercise regularly. However, for weight loss, exercise alone rarely seems to be effective.
Hack the System with Snacks
This all sounds depressing. It’s as if there’s a system in your head that has in mind how much fat you’re supposed to store. If you burn more calories than you consume, the hunger system gets turned on and stays on until you get those extra calories back.
A number of neuroscientists have proposed that the human brain regulates its weight based on an internal set point, just as a thermostat keeps the temperature relatively constant by turning the heat or air conditioning on and off.
Fortunately, there are ways to hack the system to get around this internal regulation system. Eat when you’re hungry, but make what you eat count.
Eat a small snack—one that’s rich in protein or high in fiber, or ideally both. The benefits of these types of snacks have been studied a lot. One of the best examples was a study in which people were given servings of various foods of equal caloric value.
After they finished the snack, the participants rated how full they felt. The foods that won this competition were always high in fiber and protein.
Perception and Hunger
These studies still occur today, and the losers are always foods highest in sugars and fats. Even if you consume the same calories of foods, those foods influence the leptin-ghrelin system less, resulting in less change in your perception of how hungry you are.
Lean turkey, beans, raw fruits, a smoothie with some tofu mixed in—there are thousands of examples of foods that will turn off that hunger response with only a small amount of caloric value.
Even if you have a 150-calorie snack to turn off that hunger, two or three times a day between meals, it’s better than gorging yourself on high-fat, high-calorie binges.
Prepare these snacks well in advance. Take an apple, a container of cooked beans, some carrot sticks, and a smoothie in a shakeable container with you when you leave the house in the morning.
When we’re hungry, we often lack self-control and reach for the tastiest snack in sight, which is usually not the healthiest one. By setting up high-fiber and protein-packed snacks ahead of time, we are taking back control and staving off the hunger that leads to overeating.
Dr. Peter M. Vishton is Associate Professor of Psychology at William & Mary. He earned his Ph.D. in Psychology and Cognitive Science from Cornell University. Before joining the faculty of William & Mary, he taught at Northwestern University and served as the program director for developmental and learning sciences at the National Science Foundation.