We have all heard it: snacking boosts your metabolism. It’s a myth that been going around in different forms for years and years. Tiny frequent meals can ramp up the metabolism. Always eating small keeps your body working. No matter how you hear it, it’s hard to ignore. And there must be truth to it for it to have persisted for this long. Right?

America has become a land of snacks. Most of the calories Americans eat come from snacks. Between busy schedules, marketing and convenience, snacking is a normal part of life. This is a recent phenomenon as snacks weren’t part of our culture until the ‘80s.

Digestion burns calories; it’s called the thermic effect. Your body has to use calories to breakdown food for use. People thought, logically, that eating small amounts frequently would burn more calories. The myth makes sense, to the point wherein nutritionists have even touted it and later realized it wasn’t correct. There was the belief that snacks kept “the metabolic fire stoked.”

One indicator that it’s not great advice is that eating when you aren’t hungry makes little sense. We are frequently told to stop eating when we feel satiated but are then advised that eating a snack every one-and-a-half to three hours is good for us. Eating when you’re hungry and stopping when you are comfortable makes sure you don’t become ravenous and make food choice you might later regret. But snacking when you are perfectly content can add calories to your day that your body didn’t need.

You burn the same number of calories — no matter how you consume the food. If you eat 1,800 calories over the course of a day, you will burn the same amount of calories digesting them whether you eat those calories as snacks or as three meals. One meta-analysis of data on meal frequency and calories burned over 24-hour periods saw “no difference between nibbling and gorging.” Some studies have shown that eating snacks throughout the day keeps blood glucose levels high.

But, research shows that fasting may increase the metabolic rate — if you fast for 36 hours. However, alternate day fasting, 24-hour periods of not eating, didn’t lower people’s metabolic rate. This research is relatively new and is still being performed.

So, in the end, we might be interested in cutting down on snacks. But, we shouldn’t quickly embrace the idea of fasting days, or it too may become a myth we all cling to without much proof.