These are the two biggest myths about how to lose weight, according to a Harvard nutrition expert

If you haven't tried one of these debunked weight-loss tips, then you've definitely heard of them.

Dr. David Ludwig, a Harvard Medical School nutrition and obesity expert, talked to Tech Insider about the science behind eating healthy.

His book, "Always Hungry?" outlines an evidence-based eating plan that focuses on what you eat, not just how much.

Ludwig says these are the two biggest myths about eating healthy: