5. Watching your weight, you pull way back on snacking.

Result: Less weight-loss success, more hunger, fatigue

It’s a long stretch from a noontime lunch to a 7 p.m. dinner. Snacking helps manage hunger by keeping your metabolic engine running at a more constant pace. Any healthy-eating plan should allow for one or two snacks per day: something nutritious and satisfying.

What to snack on: Calcium-rich low-fat dairy foods, full-of-fiber nuts, or naturally sweet, low-calorie fruit.