Are you overcome with self-doubt every time you unwrap a granola bar? Here, a snacking reality check.

Variety of snack options
Credit: Levi Brown

How many snacks should I eat each day?

“Most women need to eat at least every three to four hours to fend off hunger and keep their bodies functioning optimally,” says Keri Gans, a dietitian in New York City. So if you’re eating three meals, that means two healthy snacks—one midmorning and another between lunch and dinner. If you have supper four hours or more before bed, you may want to add a small after-dinner snack.

Why can’t I stop at just one?

There’s a biological reason you go back for seconds (or thirds). “You’re conditioned to polish off all the food that’s in front of you, whether it’s a bag of cookies or a bowl of pasta,” says Bethany Thayer, a spokesperson for the American Dietetic Association. Researchers at Pennsylvania State University, in State College, found that women who snacked from a big bag of chips consumed 184 more calories than those given an individually sized bag. You can work this phenomenon to your advantage by keeping the healthy bites you should eat more of—fruits, vegetables—in plain view. But if you simply must have the chips, dish out a single serving and put the rest right back in the pantry.

Should I eat a snack before my workout?

That depends on how much you’re going to sweat. Headed to a restorative yoga class? You may not need a snack unless it’s been more than three hours since your last bite. But longer and more strenuous activities, like a five-mile run or a Spinning class, might call for extra sustenance. In that case, be sure to eat your snack about an hour before hitting the gym.

Can I drink juice to help tide me over until my next meal?

Although that glass may serve up vitamins, it won’t do much for your hunger. Research shows that liquids don’t trip your brain’s satiety mechanism—the part that tells you to stop eating—the way solid food does. To more effectively stay full, pair a glass of 100 percent juice with a few nuts. Or opt for a smoothie made with juice: According to research published in International Journal of Obesity, foods and beverages with a thick consistency provide more satiety than their thinner counterparts. In the study, when volunteers were given an unlimited amount of chocolate milk or pudding, those who drank the milk consumed 30 percent more than those who ate the pudding.

If I buy prepackaged snacks, should I look for ones that are fortified?

“Not necessarily,” says Chrissy Wellington, a nutritionist at Canyon Ranch in Lenox, Massachusetts. “Adding fiber to a cookie isn’t going to transform it into something healthy.” Neither will pumping a sugary cereal bar full of vitamins and minerals. When choosing a prepackaged item, first scan the nutrition label and ingredient list to make sure it meets a few measures of the ideal snack recommendations. Then consider the value of any added nutrient. As long as you’re not already loading up on them in the form of a daily supplement, extra vitamin D, calcium, and omega-3s can all be beneficial.

Will eating a bedtime snack pack on the pounds?

Contrary to popular belief, that nighttime nibble won’t automatically be stored as fat. “A calorie is a calorie, no matter what time of day you consume it,” says dietitian Elisa Zied. “The real issue is that women tend to eat mindlessly when they relax, which usually happens after sundown.” That kind of eating can cause your weight to creep upward. Before you reach for an evening snack, consider whether or not you’re really hungry. If you are, choose a healthy option, such as a small bowl of whole-grain cereal with nonfat milk, half a peanut butter sandwich on whole-wheat bread, or low-fat yogurt topped with berries (find more low-calorie snacks here). And step away from the TV and the computer: Studies show that mindless munching is more likely to occur when you’re lolling in front of a screen.