Snack on yogurt.

Probiotics — found in yogurt products — are healthy bacteria that aid digestion. There is preliminary research connecting certain probiotics and the immune system. However, studies are unclear about the type of probiotic strains and the amount needed to reap any definitive immune health benefit. On a positive note, yogurt is a terrific source of calcium and vitamin D, nutrients that boost bone and heart health. And low–fat yogurt is a protein–rich, low–calorie snack for weight loss. So go ahead and buy these yogurts, but do it because they’re healthy and taste good — not as a cold cure!