2. Non-fat yogurt could make you binge on carbs.
Yep: Eating fat-free yogurt could have you reaching for those crackers. In a study of 120,000 people published last year in the American Journal of Clinical Nutrition, those who consumed more non-fat and low-fat dairy ate significantly more carbs overall, while people who ate more full-fat dairy ate fewer carbs. Why? Because non-fat dairy products are lower in calories, explains Mozaffarian, our bodies might seek out those calories from other sources, like carbs. And if those carbs are coming from unhealthy sources, such as oversized bagels and sugary candy, you could gain weight.
3. Full-fat is more filling.
Eating fat makes you feel full and satisfied, so eating only non-fat dairy could leave you hungrier and more prone to overeating later on. There’s a reason low-fat diets have been shown to be ineffective: They leave people hungry, and the plans tend to contain more sugar and carbs than moderate- to high-fat diets. True, the fat you’re getting from dairy is saturated, the type many experts still say we should limit (other experts, however, say saturated fat is not harmful). But your average cup of full-fat yogurt isn’t a fat bomb: Most popular brands of full-fat Greek yogurt have only 4 to 5 grams of saturated fat per 6-ounce serving. Compare that to a 6-ounce serving of ground beef, which has 10 grams saturated fat. (FYI, the USDA’s current recommended limit for sat fat is 20 grams per day).
The bottom line: Don’t pick fat-free solely because you think it’ll help you lose weight. If you prefer the taste of low-fat products and are already at a healthy weight, it’s certainly OK to keep eating them. But if you’ve been craving the richness of full-fat dairy, swapping it into your healthy eating pattern shouldn’t hurt—and could even be beneficial. “While the science continues to grow, I recommend that people eat a mix of dairy every day, and choose low-fat or whole-fat based on their own personal preference,” says Mozaffarian.