Because M&Ms contain chocolate, they also contains saturated fat and sugar, two ingredients that can be unhealthy. Snack size, called Fun Size, packages of M&Ms are small, which means you'll potentially eat fewer of the candies. You can include these as an occasional indulgence in an otherwise healthful eating plan.

One serving of the Fun Size milk chocolate M&Ms is equal to three packages, according to the M&Ms website. That serving contains 220 calories and 8 grams of fat, which is 12 percent of the fat you should have for the entire day. Of those 8 grams of fat, 5 grams are saturated, and that's about one-quarter of your saturated fat limit for the day. Too much saturated fat can raise your cholesterol levels and contribute to an increased risk of heart disease, according to the American Heart Association.

A three-pack Fun Size serving of milk chocolate M&Ms contains 29 grams of sugar, which is equal to 7.25 teaspoons. That's more than the 6 teaspoons women should limit themselves to each day and 81 percent of the 9 teaspoons men should limit themselves to daily, according to the AHA. Eating too much sugar on a regular basis can contribute to unhealthy weight gain, which leaves you susceptible to heart disease and Type 2 diabetes.

Though M&Ms can't be considered nutritious, you do get small amounts of some nutrients. A three-pack serving of Fun Size milk chocolate M&Ms contains 1 gram of dietary fiber, though that's only 4 percent of the 25 grams women need daily and less than 3 percent of the 38 grams men require each day. You'll also get 2 grams of protein, but that's only 4 percent of the 46 grams women need each day and only 3.5 percent of the 56 grams men require daily. M&Ms contain trace amounts of vitamin A and calcium, too.

The occasional Fun Size package of M&Ms can have a place in an otherwise healthy diet. The candies don't deserve a regular spot in your healthy eating plan because the amount of fat and sugar isn't worth the tiny amounts of nutrients that you do get. When you do splurge, just have one pack instead of three.