A common myth is that snacking is a perfectly healthy part of good nutrition. The theory goes that frequent eating will keep hunger at bay, supposedly allowing people to eat fewer calories overall at meals.
There’s also the disproven belief that eating frequently will boost your metabolism. In reality, snacking and how often you eat has no significant effect on the amount of calories you burn. For example, a study that had people eat the same number of calories over two or seven meals a day found no difference in calories burned.
In terms of appetite, there is some evidence that eating more frequently can actually increase hunger, especially in obese people whose hunger sensing mechanism may be off.
Another problem with regular snacking is that blood sugar and insulin stay elevated, never allowing the body to shift into fat burning mode.
Then there’s portion control, which people are surprisingly bad at, especially when eating tasty “snack” foods that are designed to be eaten in abundance. Food scientists work tirelessly to engineer your favorite snacks to stimulate parts of the brain that lead to increased food intake. Case in point: One of the most well-known food slogans is “Bet You Can’t Eat Just One” from Lay’s potato chips.
Which brings us to the real problem with snacking—what people are choosing to snack on. The reality is that if you plan your meals intelligently and opt for truly healthy low-calorie, high-fiber, high-protein snacks, you’re unlikely to have a problem. But when you choose typical snack foods and graze throughout the day, you are setting yourself up for fat gain and metabolic problems. For example, a recent publication of the National Health and Nutrition Examination Survey found that people who included snacks in their diets upped daily intake totals by an average of about 200 a day. Men got 493 calories from snacks a day while women got 360.
In theory, this could translate into gaining 1 to 2 pounds a month. Of course, real life metabolism is not so simple and most people aren’t gaining body fat at this rate, but studies do show that the average adult gains between 1 to 2.2 lbs. a year.
Additionally, frequent snacking can be harmful to metabolic organs such as the liver and pancreas. Both play critical roles in your body’s ability to burn fat and glucose, and frequent meals can impair their function and lead to fat deposition in the liver. In one trial, lean men who increased their calories by 40 percent a day by eating high calorie snacks gained more visceral fat in the belly and internal organs than a group that ate the same calories in three scheduled meals with no snacking.
Don’t get sucked into the faulty belief that snacking is categorically good for you. Most foods marketed as snacks are processed foods that are high in refined carbs and maybe some less than healthy added fiber and protein. Fiber is great for blood sugar appetite control but only when it is naturally occurring in the food. And the best protein sources are going to be foods that are naturally high in amino acids such as meat, fish, dairy, and eggs, not processed foods that have protein added to them.
Most people who are trying to manage body weight should focus on a set meal frequency that allows for fasting between eating so that the digestive system can rest and the body can shift into fat burning mode.
If you choose to include snacks, do so intelligently: Plan out portion sizes and choose truly “healthy” options. Healthy snacks are going to be the same foods that we should all be designing our nutrition around:
Vegetables, such as cut up cucumbers, celery, tomatoes, and carrots
A piece of fruit, including those that contain healthy fat like olives or coconut meat
High-quality protein in the form of a hardboiled egg, turkey or salmon slices, or Greek yogurt
Healthy fat from a small serving of nuts, seeds, or a sliced up avocado
Bellisle, F., et al. Meal Frequency and Energy Balance. 1997. 77 Suppl 1: S57-70.
Kant, A., Graubard, B. Within-person compensation for snack energy by US Adults, NHANES 2007-2014. American Journal of Clinical Nutrition.
Koopman, K., et al. Hypercaloric diets with increased meal frequency, but not meal size, increase intrahepatic triglycerides: A randomized controlled trial. Hepatology. 2014. 60(2), 545-553.
Verboeket-van de Venne, W., Westerterp, K. Influence of the feeding frequency on nutrient utilization in man: consequences for energy metabolism. European Journal of Clinical Nutrition. 1991. 45(3), 161-169.