Q: What is a healthy snack that won’t interfere with my weight loss goals? I really like a type of trail mix that contains assorted nuts, raisins and M&Ms. But the calorie count still seems high: One-fourth of a cup has 150 calories (70 from fat, or 8 grams). It has no trans fat, 3 grams of fiber, 10 grams of sugar and 14 grams of carbs.

A: The point of snacking is to provide calories between meals to infuse your body with a steady supply of energy. If you can get in key nutrients, too, all the better. A good snack is one that provides vitamins, minerals and enough calories to fuel up and curb hunger so that you don’t binge later.

How many calories your body needs when you snack depends on several things: How long it’s been since you last ate (or drank) calories, how much energy you’ve expended in the interim, and how many calories you’ll burn in the near future.

Generally a snack that’s 100 to 200 calories is considered to be sufficient. But if you’re about to head out for a 10-mile run, you might need more. Researchers at Georgia State University have found that eating every three to four hours prevents drastic fluctuations in energy intake that can lead to higher levels of body fat and poor sports performance. Sports nutrition professor Dan Bernadot provides useful eating strategies in his book Advanced Sports Nutrition.

From a calorie-only perspective, your small handful of trail mix that provides 150 calories is a good choice. But keep in mind that one-fourth a cup is a teeny amount. It’s likely that you’d eat a full cup or more and suddenly that snack turns into 600 calories—which is OK if you’re treating it as a meal or as fuel for an intense, long workout coming up. But if you’re not, then this snack may contribute to overeating over the course of the day.

If you choose trail mix without M&Ms, you end up with a healthier, lower-sugar version. Still, even though the nuts and dried fruit in a trail mix are nutritious options if you are controlling portions, you may be able to eat more and get fewer calories with other choices.

So, instead of one big handful of trail mix, or a half a cup, you could get those 300 calories by eating the following snacks instead:

Snack Option 1

• One banana
• One cup of blueberries
• Seven walnut halves

Snack Option 2

• One grapefruit
• One apple
• One slice of whole-wheat toast with one tablespoon of peanut butter

And if you eat a full cup of trail mix, you could have all of the above: four fruits, the nuts and peanut-butter toast! No matter what you nibble on, it’s a good idea to keep snacking, as long as you control portions, balance the calorie-intake along with your other meals, and choose nutritious foods.