Does steak leave you feeling funky? Is pasta putting you to sleep? You may be eating foods at odds with your metabolism, says dietitian Derek Johnson, who theorizes we all fall into one of three metabolic types:

Fat and Protein Efficient: You tend to be strong and big boned and do best on a diet of proteins and fats from fish, turkey, chicken, soy, nuts and eggs. Johnson recommends snacking on fruits or potatoes for energy, but suggests keeping simple sugars to a minimum. Since you don't digest carbs quickly, your blood sugar levels easily spike and headaches soon follow. Johnson's tip? If you're sleepy each afternoon, consider including more fat in your three main meals.

Carbohydrate Efficient: Chances are, you're tall and thin and haven't gained a pound since college. According to Johnson, you're more likely to metabolize carbohydrates quickly, and you should eat lots of them. He suggests minimizing, but not eliminating, fats and proteins and incorporating more vegetables and whole grains into your diet. His advice? Consult the glycemic index to determine which foods deliver best on complex carbohydrates (look online at www.health.harvard.edu).

Dual: A small number of people do best eating equal parts protein, fat and carbohydrate. So mix it up. According to Johnson, you should steer clear of fat-free foods because they're usually high in sugar. Fats, like those contained in avocados, almonds, and canola and olive oils, are an important part of your fat-efficient metabolic side.