A is for Alcohol
You booze, you lose: A daily serving of hooch may be better for keeping off weight than abstaining. Alcohol may increase leptin, a hormone that curbs your appetite for sweets. To get the perks with minimal calories, order a glass of sauvignon blanc (119 calories per 5 ounces).
B is for Buddies
Researchers at the University of Pittsburgh School of Medicine compared solo dieters to teams of dieters. After 10 months, the latter were likelier to have maintained their loss (66 percent versus 24 percent).
C is for Cortisol
Your adrenal glands secrete this stress hormone to help you handle threats, but too much can be bad news. Last year, researchers at the University of Leeds in the U.K. linked high levels of cortisol to increased snacking on junk food. Spend the cash you'd pay for a big dinner on a stress-reducing massage.
D is for Density
A yearlong study published in the American Journal of Clinical Nutrition found women eating water-rich foods low in calories but high in nutrients (like veggies) as part of a low-fat diet lost more weight than those who only cut back on fat. They were less hungry than the low-fat-only bunch, too, most likely because they ate 25 percent more food by weight. Go for grub with an energy density (calories per serving ÷ weight in grams of serving) of 2 or less. Or snag ideas from Barbara Rolls' The Volumetrics Eating Plan, which lists the energy densities of dozens of foods.
E is for Estimation
Developing an eye for appropriate serving sizes can make or break your diet. Commit these serving-size visuals to memory:
3 oz lean meat = a standard deck of 52 cards
1/2 cup of fruit, vegetables, or grains = half a baseball
1.5 oz cheese = 3 dominoes
F is for Fructose
A study published last year in the journal Hepatology found that feeding fructose-laced water to rats increased their risk of obesity. Ditch the artificially sweetened juices and sodas and get your fructose from fruit--a form that researchers say could be kinder to your waistline.
G is for Grapefruit
Kick off every meal with half a ruby red or 8 ounces of grapefruit juice--you could speed up your weight loss. Subjects of a 2006 study in the Journal of Medicinal Food who ate half a grapefruit before each meal lost more weight after 12 weeks than those who didn't (3.5 pounds versus less than a pound).
H is for Hydration
Studies have shown that drinking water can slightly increase your caloric burn rate. The researchers behind one such study at Franz-Volhard Clinical Research Center in Berlin estimate that sipping six extra 8-ounce glasses a day can burn 17,400 more calories (about 5 pounds of fat) per year.
I is for Insulin
The amount of this sugar-regulating hormone you secrete may dictate the diet you should follow. A study published in the Journal of the American Medical Association found that high insulin secretors dropped about 13 pounds on a low-carb diet but only about 3 on a low-fat/higher-carb diet. Look in the mirror: If you store fat in your belly (have an "apple" body shape), you're more likely to secrete excess insulin and benefit from fewer carbs.
J is for Journal
If you write down everything you eat, research has shown, you can cut your intake by 500 to 1,000 calories a day. And you'll keep the weight off: Food journaling is one of the successful behaviors used by people in the National Weight Control Registry, a list of dieters who have maintained a loss of 30 pounds or more for at least one year.
K is for Ketosis
The point at which your body runs low on carbs and starts burning fat stores for fuel, ketosis can jump-start a diet or bust a plateau. Studies show that dieters who restrict carbs typically lose more weight during the first 3 to 6 months, but after about a year their results are comparable to those who go low-fat. So after dropping those initial pounds, it's okay to have whole-grain pasta and bread again--in moderation.
L is for Leptin
Fat cells secrete this hormone to tell your brain you're full. But researchers have found that fasts and extremely calorie-restrictive diets can lower leptin levels, prompting you to eat more. To keep this hormone in balance, strive for a slow, steady weight loss--no more than 1 to 2 pounds per week.
M is for Milk
You might get better results from your workout if you imbibe moo juice. A study in the American Journal of Clinical Nutrition found that downing 2 cups of skim milk after intense weight-lifting workouts built more muscle and burned twice as much fat as drinking carbohydrate beverages (such as a sports drink). But go with real cow's milk--in the study, drinks made from soy had no effect.
N is for Numbers
Nobody enjoys weigh-ins, but research shows that people who hop on the scale once a day are more likely to lose and to maintain their loss. Make a standing appointment for yourself--just don't obsess over the number you see.
O is for Omelet
Eggs are an ideal protein source, says Jonny Bowden, Ph.D., C.N.S., author of The 150 Healthiest Foods on Earth. Protein helps build muscle, which will fry more calories per pound than fat. Bonus: You'll burn about 25 percent of the eggs' calories just by digesting them (protein metabolism uses more energy than that of fat and carbs). A two-egg omelet takes you a quarter of the way to your protein RDA.
P is for Peanuts
Subjects in a study at Purdue University received about 500 calories' worth of peanuts a day to eat at their discretion. After 8 weeks, they had gained an average of about 2 pounds--much less than the 8 pounds researchers had predicted. Probable cause: The high-protein and high-fiber nuts filled them up. And after 19 weeks, they also had boosted their resting metabolic rates by 11 percent, possibly due to the fatty acids in the nuts. Take the edge off your appetite by snacking on a handful (a quarter-cup) per day.
Q is for Quinoa
Quinoa (keen-wa) has more hunger-taming protein and fiber and less carbs than most other whole grains. Swap it for white rice and other refined grains.
R is for Replacements
Researchers at the University of Kansas found that dieters who drank liquid meal replacements lost just as much weight over 52 weeks as those who used the weight-loss drug Orlistat with regular meals. Who needs pills?
S is for Stress
Scientists at Georgetown University fed two groups of mice a diet of high-fat, high-sugar feed and measured how much weight they gained. Stressed mice (you don't want to know how they pushed them over the edge) gained more than twice as much weight as the group with the same diet but no stress. The reason? Researchers believe that stress causes the release of a molecule that helps increase the size and number of fat cells. The next time you're feeling the strain, do yoga (see Y) instead of dessert.
T is for Tea
The fat-busting benefits of green tea boil down to disease-fighting compounds called catechins. One study of 240 Japanese men and women found that when subjects drank green tea containing 583 milligrams of catechins per 12-ounce cup, they dropped more weight--and inches--than those who ingested tea containing only 96 milligrams. Max your results by steeping your bag of green tea as long as possible. The darker the hue of your brew (and the more bitter it is), the more catechin-rich the cup.
U is for User-Friendly
A recent study in the Journal of the American Medical Association assigned 160 overweight and obese volunteers to one of four popular diets for 6 months. They found that the strongest predictor of weight loss wasn't the type of diet but compliance with the selected plan. The takeaway: Find a plan you can live with so you'll stick to it.
V is for Vinegar
A study published in the Journal of the American Dietetic Association found that swallowing 60 grams (about 4 tablespoons) of an apple cider vinegar mixture with a high-glycemic-index meal caused test subjects to eat 200 to 275 fewer calories over the rest of the day. If you can't stomach the stuff straight, try mixing it into a low-fat dressing.
W is for Weights
If you've put off pumping iron, get to it. According to experts, you burn calories faster after a strength-training session than you would after a cardio session. And researchers at the University of Alabama at Birmingham found that lifting weights three times a week for 25 weeks caused women to lose an average of 4 pounds of body fat.
X is for Xenical
This prescription fat blocker made news last year when the FDA greenlighted its over-the-counter version, Alli. But both drugs come with an unfortunate side effect: loose stools. We say pass on the gas and slim down the old-fashioned way.
Y is for Yoga
A study at the Fred Hutchinson Cancer Research Center in Seattle found that normal-weight women who practiced yoga for four or more years gained three pounds less over 10 years than those who didn't. Grab a mat and get going.
Z is for Z's
When you skimp on sleep, your brain thinks you're low on fuel and sends a message to your stomach to start growling. A study published in the American Journal of Epidemiology found that among 68,183 women, those who slept for 5 hours or less were an average of 5 pounds heavier than women who snoozed for 7 hours. Want to stay slim? Go to bed.