Better butt diet: the wrong diet can sabotage your workout efforts. Follow these 6 steps to get your rear in gear

In the battle of diet vs. exercise, DIET IS THE ULTIMATE CHAMPION. It's sad but true: Even the best workout program can be undermined by just a few slips of the fork.

"Nutrition is unquestionably the No. 1 problem for people who aren't reaching their goals," says fitness model, triathlete and personal trainer Kristia Knowles. "I always tell people that nutrition is key."

Think of nutrition as the foundation of a good fitness program. If your goal is to lose bodyfat and reveal your muscles, follow our six-step program to get the results you want, not just in shaping better legs and glutes but for your whole body. We've made it easy with 21 healthy meals and snacks that you can mix and match.

Nutrition isn't an exact science but rather a process of trial and error--finding what works best for you and then trying to stay consistent. Tailor the tried-and-true advice here to your personal preferences so you can finally show off your hard-earned muscle and maximize your workout results.

1 LIMIT ADDED SUGAR

"DON'T EAT DOUGHNUTS," jokes figure competitor Monica Brant when asked how to lose fat. The Los Angeles fitness model explains that natural sugar in fruit is okay, but you want to minimize your intake of foods with added sugar. "There are a lot of hidden sugars in processed foods we eat," adds Kristia, who calls Daytona Beach, Florida, home. So, simply choose the plain oatmeal rather than flavored. Go for all-natural peanut butter over commercial brands such as Skippy or Jif. Read food labels and try to find products without ingredients such as high fructose corn syrup. Better sources of energy-providing carbohydrate include:

* whole-grain bread, tortillas and pita

* whole-grain crackers such as Ak-Mak

* brown rice

* oatmeal

* dry cereal with at least 5 grams fiber per serving

* all fruits and vegetables

2 EAT PROTEIN WITH EACH MEAL

PROTEIN WILL KEEP YOU FEELING FULLER than eating a meal containing mostly carbohydrate and provides your body with critical muscle-repairing amino acids. Monica strives to consume 1 gram of protein per pound of bodyweight each day while Kristia tries to eat 20-25 grams of protein at each meal. Strive to include a portion of protein at each meal and snack, so you'll stave off hunger and feel satisfied throughout the day. Good sources of protein include:

* skinless chicken breast

* eggs and egg whites

* extra-lean or lean ground turkey

* tuna or salmon

* soy products such as edamame, soy crumbles and tofu

* dairy such as cottage cheese, fat-free milk and reduced-fat cheese

* beans

* nuts and seeds (high in calories, so keep portions small)

3 EAT FEWER CARBS AT NIGHT

DURING THE DAY you need carbohydrate to fuel your brain and body, especially if you exercise. In the hours before bedtime, however, limit the amount of pasta/bread/rice/potatoes that you eat. Many fitness models and competitors eliminate all such starchy carbs at night, but you don't have to go that far. Just keep the portions about the size of your clenched fist. This can be difficult, especially at restaurants or when sharing a meal with family. To get yourself on the right track, mentally "coach" yourself before dinner: Think about how much you'll be eating and resolve to pay attention to the portions on your plate. Then, fill up that salad or soup bowl to the brim!

4 ... BUT DON'T ELIMINATE ALL CARBS

LET THE LOW-CARB BANDWAGON PASS YOU BY if you're a fitness buff. "Active women need to eat carbohydrates," explains Kristia. "The brain uses carbohydrate and needs glucose to function. If you're active, a [low-carb diet] might make you feel lethargic and tired."

When choosing your carbs, try to pick those with the shortest ingredients list and a label you can actually understand.

Also realize that many low-carb versions of your favorite foods may be either chock full of fat or artificial sweeteners. Neither is the best choice for your health.

5 DON'T OBSESS OVER NUMBERS

THIS GOES FOR CALORIES, fat grams, carb grams, pounds on the scale and any other number related to weight. First, unless you've got a set of measuring cups and spoons attached to your belt, precisely counting calories is virtually impossible. Second, even if you cut 3,500 calories from your diet in a week (the general recommendation to lose 1 pound), this does not automatically mean you will lose 1 pound. Your metabolism fluctuates daily depending on your activity level, diet and possibly even the time of the month. Strive to be consistent overall rather than micromanaging every bite you eat.

Remember the simple rule that your hand gives the ideal portion size. A 3-4-ounce serving of protein should fit in the palm of your hand; a perfect serving of pasta is the size of your clenched fist.

6 GO FOR THE TOTAL PACKAGE

FITNESS COMPETITOR ANNA LEVEL reminds us that success depends on three factors--aerobic activity, weight training and proper nutrition. She offers these general rules: