The Best One-Day Diet Solutions

Spanx can solve a lot of life's problems, but they can't make you look better in your birthday suit.
Nor can they tame PMS, perk you up after one too many cocktails, or keep you revved in bed. But the right foods can.

Don't let the dreaded D-word throw you off. These daylong diets aren't about deprivation or even losing weight; they're about noshing on the right nutrients so that you'll look better and feel better--fast.

"We Leave for a Romantic Getaway Tomorrow" Diet
Your sexual vitality depends on eating foods that are rich in the amino acid L-arginine, says Robert Fried, Ph.D., senior professor of biopsychology at Hunter College and coauthor of Great Food, Great Sex. Found in nuts, poultry, and seafood, this sexual secret weapon promotes healthy blood flow to the sex organs so you can experience maximum pleasure.

Also, devouring heavy foods before the big lovefest can weigh you down and divert blood flow away from your sexual regions. Reach for lighter fare that balances carbs (for energy), protein (for stamina), and healthy fats (which your body uses to produce testosterone and estrogen, the two hormones that keep your libido running nicely).

What to Eat
* Breakfast Oatmeal + walnuts + dried cranberries
* Snack Celery + peanut butter
* Lunch Garden salad + chicken + olive oil dressing
* Dinner Whole-wheat pasta and shrimp tossed in olive oil + fresh-berry dessert

TRY THIS: The 2 Day Cleanse That Isn't Crazy

"I'm in PMS Hell" Diet
Premenstrual mood swings and crazy cravings come down to a shortage of the brain chemical serotonin, says Judith Wurtman, Ph.D., coauthor of The Serotonin Power Diet. "The only thing that helps-and it helps instantly--is to eat carbs, because that's the only way the brain makes new serotonin," says Wurtman, who adds that the serotonin boosters need to be eaten straight with no fat or protein (think sweet potatoes or a whole-wheat English muffin without butter). No, this isn't a license to go all-day carb crazy--just when your PMS tends to be at its worst, which is usually late afternoon and evening. "The rest of the day, fill up on fruits, vegetables, and protein, which can help curb your cravings and keep you satiated," says registered nutritionist Joey Shulman, author of Healthy Sin Foods: Decadence Without the Guilt. Also, forgo salt and get more of the nutrients that have been linked with lessening those heinous that-time-of-the-month symptoms: magnesium (grains, nuts, greens), and calcium and vitamin D (dairy, fortified OJ).

What to Eat
* Breakfast Cottage cheese + berries + fortified OJ
* Lunch Spinach salad + salmon + low-fat milk
* Snack Air-popped popcorn (no butter) drizzled with fat-free chocolate sauce
* Dinner Whole-wheat pasta with garlic, mushrooms, and onions in a tomato sauce

"I Want to Look Fab on My Date Tonight" Diet
It's one thing to look good in your little black dress, but it's even more important to look good if it comes off. Certain food combos (protein plus carbs) can make the tummy tent up, says Esther Blum, R.D., author of Secrets of Gorgeous. So she recommends pairing protein with vegetables and fat, or carbs with veggies and fat. Banish bloat inducers such as beans, broccoli, cabbage, cauliflower, carbonated drinks, and artificial sweeteners, and fill up on high-water foods instead (cucumber, watermelon, pureed soup). "These will hydrate the system and help flatten the stomach," Shulman says. Bromelain, a digestive enzyme in pineapple, also works wonders by breaking down protein and amping up digestion. Got water-retention woes? Skip salt-laden foods (that includes all takeout) for potassium powerhouses like avocados and bananas, which will help get rid of the extra fluid. If constipation is the culprit, insoluble fiber found in fruit and wholegrain products can relieve you. Psst: Peppermint tea can decrease bloating gas and speed up digestion.

What to Eat
* Breakfast Fruit smoothie (peaches, strawberries, banana, pineapple, yogurt)
* Lunch Chicken Caesar salad with avocado
* Snack Peppermint tea + cucumber sticks
* Dinner Low-sodium soup + steamed salmon or chicken

PLUS: 5 Fatty Foods That Make You Skinny

"I Need to Be on Top of My Game for Work" Diet
Before a morning powwow, make sure you have some protein. "Otherwise you're going to be brain dead," Wurtman says. The amino acid tyrosine in protein makes you mentally alert. A latte lift and pastry pickme-up may seem like the answer, but "too much caffeine can make you jittery and could increase stress," says Melina Jampolis, M.D., diet and fitness expert for CNN. Limit the caffeine and avoid clarity-clouding white stuff (white flour, white sugar, white pasta) in favor of complex carbs like bran muffins and whole-wheat bread. "They metabolize more slowly to keep your blood sugar and energy on an even keel," says Cheryl Forberg, R.D., nutritionist for NBC's The Biggest Loser. Studies also show that vitamin C may act as a chill pill and help you bounce back faster from high-pressure situations. Also, "iron deficiency can make you feel sluggish by decreasing your ability to carry energy-essential oxygen," Jampolis says, so opt for iron-rich foods such as beans and lean beef.

What to Eat
* Breakfast Scrambled egg whites + whole-wheat cereal + orange
* Lunch Taco salad (salad greens + kidney beans + lean ground beef)
* Snack Low-fat bran muffin + water

PLUS: How to Burn More Calories While You Sleep

"I Shouldn't Have Had That Third Martini" Diet
After a big night out, you may feel more like praying to the porcelain god than eating, but the right food can pep you up and sideline those sangria-induced symptoms. Gay Riley, R.D., founder of NetNutritionist.com, suggests starting the day with a high-protein, low-carb breakfast paired with fresh vegetable juice to replenish energy. Korean researchers also give a hangover-nixing nod to asparagus, which boosts key enzymes that break down alcohol. Add more detox bang to your breakfast with turmeric-topped egg whites, suggests nutritionist Christine Avanti, author of Skinny Chicks Don't Eat Salads. Curcumin, a bioflavonoid in turmeric, coupled with cysteine, an amino acid in eggs, helps mop up hangover-causing toxins such as acetaldehyde. Other morning-after picks include vitamins B6 and B12 (found in cereal and salmon) and headache-helping magnesium and potassium (in peanut butter and bananas). And despite what you may have heard, a Bloody Mary won't help; the alcohol will only further tax your liver. But straight-up tomato juice is full of potassium, as well as alcohol-burning fructose. Also drink water or nausea-relieving ginger tea.

What to Eat
* Breakfast Bacon + egg whites with turmeric + tomato juice
* Lunch Fortified breakfast cereal with low-fat milk + ginger tea
* Snack Greek yogurt + banana with peanut butter
* Dinner Salmon + baked potato

By Allison Young, Women's Health

More from Women's Health:

10 Things That Slow Your Metabolism

12 Foods for a Flat Belly

Run a 10-K, Feed 10 People! Learn More