The Metabolic Effects of Snacking

The Metabolic Effects of Snacking

Over the years, American has evolved into a nation of snackers. In fact, most of the calories Americans consume are in the form of snacks. Why the growth of between-meal nibbles? Busy schedules sometimes make it difficult to sit down to a structured meal. “Grab-and-go” and erratic eating schedules have become a way of life for many. Rather than eating less often, snackers usually end up eating more often than three times a day. How does all of this snacking impact metabolism, and does it make it easier or harder to control weight?

 The Frequent Meal Theory

“Eat something every few hours.” You’ve probably heard this more than once. At one time, dieticians and fitness professionals advocated eating three small meals a day and two snacks based on the idea that eating every few hours helps control appetite and reduces cravings. While eating frequently sounds logical, assuming you’re making the right snack choices, science doesn’t necessarily support the benefits of doing so. In fact, a Spanish study showed snackers were MORE likely to gain weight over the 4.5 year period that researchers followed them.

Other studies show snacking MAY help with weight control. One study involving 2,700 middle-aged adults found those who ate 6 or more times daily consumed fewer calories and had a lower BMI than those who consumed less than 4 meals or snacks a day. Don’t you love conflicting data?

As you can see, science isn’t clear on whether snacking is a positive or negative for weight control. One reason studies show such contradictory results is they depend on self-reported snack habits and people often underreport how much they eat. Plus, a snack could consist of healthful foods like fruits and nuts or less healthy ones like chips and other packaged snacks. The types of snacks you eat would surely impact whether or not you gain or lose weight.

Interestingly, research shows the best type of snack for appetite control is one that’s high in protein. That’s hardly surprising since protein is more satiating than fat and carbohydrates. The appetite-curbing power of protein can help you eat less later in the day or at your next meal or snack.

 Does Eating Frequently Boost Your Metabolism?

Another argument for eating frequent mini-meals or snacks is the idea that doing so boosts your metabolism. You DO burn additional calories when you break down macronutrients from the food you eat, particularly protein, but the effect is small. Thermic effect of food, the additional energy you burn digesting your food each day, accounts for only 10% of your metabolic rate. Plus, newer research shows the additional calories you burn is independent of how many meals or snacks you eat.

What counts is the total amount of food you eat each day, regardless of when you eat it. For example, if you consume 1,800 calories per day, it makes no difference whether you eat three 600-calorie meals or six 300-calorie meals. The idea that you’re revving up your metabolism and sending it into overdrive every time you eat a snack may only be a pipe dream – but it sure sounded good, didn’t it?

Snacking and Blood Sugar

You might wonder how snacking affects other aspects of your metabolism, like how your body processes glucose. Studies are somewhat conflicting here too with most research suggesting that eating regular meals, three times a day, improves insulin sensitivity and glucose control, but the quality of what you eat or snack on matters. All bets are off if you nosh down on processed carbs at each meal.

As further confirmation of this, a study showed eating six carbohydrate meals led to higher glucose levels throughout the day than eating three carby meals while adding protein to the meals improved glucose metabolism and the insulin response to those meals. There’s that protein thing again! The take-home message? If you snack or eat small meals throughout the day, make sure they’re high in protein, but based on most of the literature out there, eating three times a day is better for glucose control.

The Bottom Line

Sadly, the commonly circulated advice of eating many small meals or snacks over the course of a day to help control weight isn’t strongly supported by science. On the other hand, we’re all a little different. Some people DO find that eating frequently helps with appetite control. If that’s the case, you may want to eat more frequently, especially if it tames your desire to eat the “wrong” foods and leads to decreased calorie consumption overall. If you eat multiple small meals, make sure what you’re eating includes a source of lean protein.

 Here are some high-protein snack ideas:

.   Cottage cheese – a single serving has 10 grams of protein!

.   Hard-boiled eggs – easy to carry with you and quite filling

.   Almond butter on whole grain crackers – Skip the vending machine. This is better for you than processed peanut butter nabs.

.   Edamame – protein AND fiber

.   Hummus on whole grain crackers

.   Greek yogurt – lower in carbs than regular yogurt

.   Make your own protein bars – Most commercial protein bars, with a few exceptions, are either too high in sugar or contain a long list of ingredients with chemical names. Make your own using one of the many recipes available online.

.   A handful of nuts – Don’t get carried away as is easy to do. Set aside a serving and don’t eat out of the can or bag.
The take-home message: Snacking and eating mini-meals throughout the day won’t ramp up your metabolism any more than consuming the same number of calories in three meals. Still, there are times where eating a snack will work best for you, for example, before or after a workout. Just don’t count on it to rev up your metabolism.

The major benefit to eating every few hours is to control appetite, and, assuming you’re consuming protein, a more sustained energy level. Protein helps to moderate the swings in blood sugar that make you feel tired and zapped of energy. Another element to include in your meals and snacks is fiber. The combination of protein and fiber fills you up and helps stabilize your blood sugar.

When you snack, do it smartly and choose your snacks carefully. Don’t use snacking as an excuse to eat sugary foods or processed carbs.



J Am Diet Assoc. 2011 Dec; 111(12): 1898-1903. doi:  10.1016/j.jada.2011.09.012.

NewsMax Health. “Study Uncovers Healthiest Type of Snack”

Food and Nutrition. “What Science Says about Snacking”

Am J Clin Nutr January 2005 vol. 81 no. 1 16-24.


Related Articles By Cathe:

How to Stop Eating after Dinner and Avoid Weight Gain

5 Ways to Naturally Curb Your Appetite That Are Backed by Science

Pistachios: the Perfect Snack

Is the American Diet Changing for the Better – or Not?

Does Frequent Snacking Help With Weight Control?

5 Snacking Mistakes That Make It Harder to Stay Lean

What Your Exercise Recovery Diet May Be Lacking



Hi, I'm Cathe

I want to help you get in the best shape of your life and stay healthy with my workout videos, DVDs and Free Weekly Newsletter. Here are several ways you can watch and work out to my exercise videos and purchase my fitness products:

Get Your Free Weekly Cathe Friedrich Newsletter

Get free weekly tips on Fitness, Health, Weight Loss and Nutrition delivered directly to your email inbox. Plus get Special Cathe Product Offers and learn about What’s New at Cathe Dot Com.

Enter your email address below to start receiving my free weekly updates. Don’t worry…I guarantee 100% privacy. Your information will not be shared and you can easily unsubscribe whenever you like. Our Privacy Policy