33 Ways To Stay Lean for Life

"It's not rocket science." If you've asked for tips on losing weight—and keeping it off for good—chances are, somewhere along the way, you've heard that phrase. (Just as likely: You heard it from someone who was cut from marble.) But you know what? Losing weight is still very much a science, especially if you want to do it effectively and permanently.

After all, can you tell the nuanced disparities that exist in different types of cholesterol without science? Or could you name the simple post-lunch habit that's keeping you from shedding pounds per year? Well read on, because we tracked down 33 scientist-approved studies that are all but guaranteed to help you shed pounds and stay lean for the rest of your life. And for great more advice on living your best life, follow us on Facebook and sign up for our newsletter now!

Nuts might have a high fat content, but munching on them doesn't promote weight gain, according to a meta-analysis of studies reported in the Journal of Nutrition by researchers at Purdue University, Penn State University, and Temple University. In fact, eating a handful of chestnuts, almonds, or peanuts has a high satiating effect, helping to curb your appetite and prevent the accumulation of extra pounds.

Also, some of the fat content in nuts is flushed from the body before it settles around the midriff, say the researchers. Unsalted raw or dry-roasted varieties are the healthiest. Want more healthy food ideas? Check out the 13 Healthiest Food Combos for People Over 40.

Eating lean red meat trimmed of visible fat can help lower your cholesterol and won't contribute to weight gain, making it almost as healthy as chicken or pork, according to a review of 54 nutrition studies at China's Zhejiang University. Red meat is also a key source of vitamin B12–an essential building block of red blood cells and nerve tissues.

Choose a less marbled beef cut such as top round, top sirloin, or round tip, and monitor your portion size. "A typical 12-ounce steak represents nearly twice the recommended daily allowance of red meat for an active 40-year-old man," says James Hill, PhD, director of the Center for Human Nutrition at the University of Colorado Health Sciences Center.

It's also important to rotate other sources of lean protein such as chicken, fish, and legumes into a healthy diet that contains red meat. Plus, pairing your steak with red wine, which contains powerful antioxidants called polyphenols, can help reduce the oxidative stress of digesting the meat, according to a study in the Journal of Agricultural and Food Chemistry.

When it comes to beer bellies, what matters isn't how often you imbibe, but how many brews you throw back, according to data from the CDC.

Researchers found that men who tipple two 12-ounce beers (or two five-ounce servings of wine) a day are 48 percent more likely to be obese than those who stop after one drink. Consuming three or more beers led to an 80 percent jump in obesity. But don't become a teetotaler: "A drink or two a day can reduce your risk of heart attack," says Steven Lamm, M.D., author of The Hardness Factor. "But stick to a two-drink max and make smart choices about food and exercise. Having more than two drinks a day also increases the risk of stroke and high blood pressure."

Vegetable oils containing oleic acid–also known as omega-9–can increase satiety between meals, according to a study in the journal Cell Metabolism.

Researchers at the University of California at Irvine found that infusing oleic acid into the intestines of rats enabled the release of oleoylethanolamide (OEA), a lipid that activates nerves in the small intestine that are responsible for signaling the brain that the stomach is full. "Add oleic acid to your meals by stir-frying vegetables in one to two tablespoons of olive oil over medium heat," says Susan Dopart, a registered dietitian. Grapeseed oil is also rich in oleic acid. Take a look at some more heart-smart foods with the 10 Best Heart Healthy Additions to Your Diet.

Eggs have long ruled the breakfast roost, so to speak, and research confirms their nutritional place at the head of the table: Eating two eggs in the morning can speed up weight loss, according to a study in the International Journal of Obesity.

Overweight participants ate a 340-calorie breakfast of either two eggs or a single bagel five days a week for eight weeks. Those who ate eggs (including the yolk, which contains nearly half the protein) reported higher energy levels and lost 65 percent more weight than bagel eaters–and with no effect on their cholesterol or triglyceride levels. Plus, a study in the British Journal of Nutrition concluded that consuming high-quality proteins such as eggs earlier in the day results in more sustained fullness compared with eating similar meals in the afternoon or evening.

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Ever wonder why you continue to gorge yourself at meals even after you feel full? Blame free radicals. A study by researchers at Yale University School of Medicine discovered that when your stomach is full, free radicals attack neurons called POMCs, which help control your appetite. The result: a negative feedback loop that impairs your ability to judge when hunger is satisfied.

Escape the cycle of overindulgence by eating small meals (around 400 calories) throughout the day that contain lean proteins such as grilled chicken, fish, or turkey, and scooping up free radicals with more servings of spinach, apples, and rich sources of omega-3 and omega-6 fatty acids such as avocados, walnuts, ground flaxseed, and olive oil, says nutritionist Kyle Brown. Keep those hunger pangs in check with the 27 Smartest Ways to Control Your Cravings.

You can reverse the drop in bone density that accompanies most diets by adding more low-fat dairy, according to a study in The Journal of Nutrition. Researchers divided 130 people into two groups: One group ate a high-carb diet with two servings of dairy a day, while the other ate a high-protein diet with three daily servings of dairy. Both groups lost similar amounts of weight, but bone density remained stable for the high-protein dieters and declined for the high-carb sample. To get your three servings of dairy a day, registered dietitian Keri Glassman recommends a cup of skim milk with breakfast, a cup of nonfat yogurt with lunch, and an ounce of low-fat cheese with dinner.

Don't gulp down a marketing gimmick the next time you order a drink. Because each additional ounce of a typical soft drink adds 11 calories, registered dietitian Lauri Lang suggests ordering bottled water or packing a drink that will boost your nutrient intake, such as a low-sodium V8 juice.

Researchers from the University of Kansas Energy Balance Laboratory just might have found the simplest solution to weight control: calcium. They had 50 previously sedentary participants start exercising, and half of them took 1,000 milligrams of calcium a day. After nine months, the men taking calcium lost up to 14 pounds, almost 50 percent more than those who simply exercised.

The researchers speculate that calcium helps regulate fat metabolism during exercise, altering how much stored fat can be used for energy. The recommended daily intake of calcium is 1,000 milligrams, but because an eight-ounce glass of milk contains only 285 milligrams of calcium, it's likely that you aren't getting enough. Yogurt, mozzarella cheese, and spinach are also rich sources of calcium.

Every time you resist a piece of pie or a bagel with extra cream cheese, you decrease your chances of being able to do it again. That's because the ability to control oneself wanes over time, according to a study from Florida State University. The researchers determined that maintaining a steady blood-sugar balance is important for self-control.

"There are two ways to moderate blood sugar," says registered dietitian Valerie Berkowitz. "First, eat foods that keep it stable, like peanut butter on a celery stalk or other high-fiber foods. Second, exercise with weights to increase your muscle mass, because this will improve your body's ability to control blood-sugar spikes."

Chew gum after lunch and you'll snack on 36 fewer calories throughout the rest of the day and feel less hungry, according to a study in the journal Appetite. That might not seem like a lot, but a separate study in the Journal of the American Dietetic Association found that simply cutting a few calories—with or without exercise—is one of the most effective ways to keep the pounds off over the long haul. Thirty-six calories a day translates to more than three pounds a year.

Drinking black tea makes high-carbohydrate meals a little healthier, according to a new study in the Journal of the American College of Nutrition. People who drank a cup of black tea after eating high-carb foods decreased their blood-sugar levels by 10 percent for two and a half hours after the meal. Escaping the dreaded sugar spike and crash means you'll feel full longer and eat less. The researchers say the polyphenolic compounds in the tea increase circulating insulin, which lowers blood sugar.

Here's proof that less can indeed be more: Stocking your shelves with snack food in small 100-calorie packages might not help you lose weight, according to a study from Brown University. The researchers found that packaging cookies, chips, Goldfish, and M&Ms in smaller serving sizes has no effect on how much people devour. The biggest predictor of how many calories you consume is the amount of food available in your home. The problem with portion control is that if you're not full when you've finished the package, you're going to eat more. Nutritionists say you should focus on snacks that are high in protein, fiber, and water volume, like fruits and vegetables, which keep you full with fewer calories.

Eating a diet that's rich in protein reduces abdominal fat, according to two Australian studies. The first study looked at 100 overweight men and found that those whose diets were high in lean red meat and fiber lost the most weight around their waists. The second study, in the American Journal of Clinical Nutrition, found that people on high-protein diets (more than 88 grams of protein a day) lost more weight than those who reported lower protein intake. Lean cuts of grass-fed beef are the best choices for healthy weight loss.

Too many of us are drinking the Kool-Aid: The number of calories we drink increased by 93 percent since 1965, according to a study in the journal Obesity. The researchers estimate that sweetened beverages account for most of this increase and that we consume 222 extra calories a day from beverages alone. The worst news about these extra calories is that they provide no additional nutritional benefit. For a healthy carbonated alternative to soft drinks, mix 100 percent fruit juice with seltzer water to make a fruit spritzer.

Whole-grain foods can shrink your belly. Researchers from Penn State University put 50 obese adults on a restricted-calorie diet; half the participants replaced all refined grains with whole grains, and the other half avoided whole grains. While both groups lost weight, the whole-grain eaters lost 2.4 times more belly fat than those who ate refined grains. Choose whole grains such as brown rice, oatmeal, and 100 percent whole-grain breads and pastas to shrink your gut.

A study in the Journal of Nutrition found that eating eggs increases your amount of good cholesterol (HDL) but not bad cholesterol (LDL). Because of its nutrient density, an egg will keep you satiated longer than most foods. Add to that a recent study in the Journal of Gerontology, explaining how dietary cholesterol actually helps you build muscle mass, and you have the return of the perfect hard-boiled snack.

Trans fats are not only worse for your heart than other fats, but they're also a prime culprit for weight gain. While mono- and polyunsaturated fats are not associated with weight gain, for every 1 percent increase in the percentage of calories you consume from trans fats, you gain 2.3 pounds.

Go ahead and order that lumberjack breakfast. Eating more of your daily calories at breakfast will keep you from gaining weight, according to a report in the American Journal of Epidemiology. After following 6,764 healthy, fit people for almost four years, researchers found that those who ate 22 percent of their daily calories in the morning (about 550 calories for a 2,500-calorie diet) gained only 1.7 pounds in that time. Those who ate less than 11 percent of their calories at breakfast gained 2.7 pounds.

In case you haven't heard, fat isn't all bad. Unfortunately, in 2017 people have replaced fat with sugar and carbohydrates, which has increased Americans' total caloric intake and set them up for a host of metabolic disorders. A healthy, balanced diet should emphasize vegetables, fruits, beans, unrefined whole grains, and mono- and polyunsaturated fats, with a lighter emphasis on yogurts, cheeses, poultry, fish, and lean beef.

Probiotics, friendly bacteria like those found in yogurt and pickles, may be the key to losing those last stubborn inches around your waist. They not only help the digestive system work properly, but also have a profound effect on the metabolism, according to a study in Molecular Systems Biology. The bacteria Lactobacillus paracasei and Lactobacillus rhamnosus can change how much fat is available for the body to absorb by influencing stomach acids during digestion. The best sources of live bacteria are yogurt, acidophilus milk, miso soup, soft cheeses, pickles, and sauerkraut.

Research conducted at Purdue University linked artificial sweeteners such as saccharin and sucralose to weight gain. In an animal study, the researchers found that ingesting regular sugar, rather than zero-calorie substitutes, results in fewer overall calories consumed. The scientists believe that disrupting the connection between sweet taste and high caloric content makes people crave more food.

Eliminating just 100 excess calories a day is enough to prevent a five- to 10-pound weight gain (the former if you're active, the latter if you are a couch potato). The best way to cut calories is to eat a diet that's high in protein and low in carbohydrates, according to a study in the American Journal of Clinical Nutrition. The researchers found that diets high in protein (30 percent of total calories) and low in carbs (4 percent of total calories) are best for reducing calorie intake without increasing hunger. Three slices of bacon is approximately 100 calories.

Americans eat until external cues, such as an empty plate, tell them to stop, says a study in Obesity. The French use internal cues, such as no longer feeling hungry, to determine when a meal should end. The lesson: Listen to your stomach and you'll stay slim.

Punching the concept of the beer belly right in the gut, Danish researchers recently reported that the more frequently you drink alcohol, the lower your odds of a major increase in belly girth.

The researchers studied the drinking habits and measured the waist-circumferences of 43,543 adults over five years. To their surprise, frequent drinkers—up to 28 drinks a week for men—were 17 percent less likely to have gained inches around the middle than those who had only one drink a week. "This fits with other recent research," says endocrinologist Michael W. Lee. "Moderate alcohol intake–up to two drinks a day–has health benefits."

Thanks to its heart-healthy attributes, olive oil has ruled the oil roost, but coconut oil might be a better choice. Coconut oil is made up of more than 50 percent medium-chain triacylglycerol (MCT), a fatty acid that increases fat oxidation, enhancing weight loss, according to a study in the American Journal of Clinical Nutrition. Researchers had people consume four or five teaspoons of MCT oil or olive oil a day for 16 weeks, either baked into muffins or used in a stir-fry. The MCT group lost almost four pounds more than the olive-oil group.

If you're not overweight, eating a high-protein, high-fat snack will increase your metabolic burn. When researchers from Georgia Southern University had people eat either two Atkins Advantage bars (a high-protein, high-fat snack with 37 grams of protein and 21.2 grams of fat) or two OmegaZone bars (a high-protein, low-fat snack with 30.8 grams of protein and 11.8 grams of fat), they found that although each snack provided 440 calories, the Atkins bars increased the metabolic burn rate for the normal-weight Atkins group for three and a half hours after eating. Bottom line: Eat a high-protein, high-fat snack (such as salmon jerky or almonds) to increase your calorie burn for hours.

Call them the flat-belly rules. Men who lose weight successfully and keep it off share the following eight characteristics, says Suzanne Phelan, Ph.D., an Associate Professor of Kinesiology at California Polytechnic State University: They eat an average of 1,850 calories a day, with 27 percent coming from fat. They burn 3,293 calories a week exercising. They watch fewer than 10 hours of TV a week. They weigh themselves daily. They eat the same way on weekends and holidays as they do on weekdays. They eat breakfast every day. They limit diet variety. And they rarely eat fast food.

Whole-grain foods help keep you slim because their high fiber content lets them move through the body without raising hormone levels and inciting fat storage. But not all fiber has these benefits. Sneaky manufacturers often add isolated fibers such as inulin and maltodextrin to foods so that they can make fiber claims on their packaging, but these are no substitute for whole grains.

"In the form of whole grains, the fiber encapsulates the carbohydrate, slowing its absorption," says Walter Willett, M.D., a professor of epidemiology and nutrition at the Harvard School of Public Health. "Just adding isolated fiber on top of a refined carbohydrate isn't the same."

Sarcopenia, the steady loss of muscle mass, threatens every one of us after we hit 40–but there might be a way to slow it down. Researchers at the Department of Agriculture's Human Nutrition Research Center on Aging, at Tufts University, found that foods rich in potassium help preserve lean muscle mass. After studying 384 volunteers for three years, they found that those whose diets were rich in potassium (getting more than 3,540 milligrams a day) preserved 3.6 more pounds of lean tissue than those with half the potassium intake. "That almost offsets the 4.4 pounds of lean tissue that is typically lost in a decade by healthy men," said study author Bess Dawson-Hughes, M.D.

While bananas are the easiest on-the-go source of potassium (each contains about 420 milligrams), there are better sources of the nutrient. Here are 15 of the best:

Food                                      Serving size        Potassium (in MG)
Swiss chard, boiled                 1 cup                            961
Lima beans, cooked                 1 cup                           955
Yams, cooked                          1 cup                             911
Acorn squash, baked               1 cup                           896
Spinach, boiled                        1 cup                            839
Papaya                                        1 whole                       781
Pinto beans, boiled                  1 cup                           746
Crimini mushrooms, raw        5 oz.                           636
Cod, baked or broiled              4 oz.                           586
Beets, boiled                           1 cup                             518
Broccoli, boiled                       1 cup                            457
Brussels sprouts, boiled         1 cup                           450
Cantaloupe                              1 cup                            427
Tomato, raw                           1 cup                             427
Banana                                    1 whole                         422

When researchers from the University of Pennsylvania questioned the accepted wisdom that adults should drink eight eight-ounce glasses of water per day for optimum health, it sent ripples through the science community. They asserted that there's no evidence that water cleans out toxins, wards off weight gain, improves skin tone, or has any beneficial health effects.

A study in the British Journal of Nutrition shifted the emphasis onto the kind of water you drink. Researchers found that drinking carbonated beverages increases satiety and decreases the amount of calories consumed. While the study authors aren't suggesting you drink soda to lose weight, their research suggests that sparkling water may decrease cravings more than still water.

Contrary to popular nutritional advice that promotes regular snacking, a study presented to the Dietitians Association of Australia found that eating more than three times a day does not contribute to weight loss. The researchers found no difference between those who ate three meals a day and those who ate three smaller meals and three snacks a day.

In recent years, nutritionists have warned that fruit juice is a sugary indulgence that costs more in calories than it's nutritionally worth. But studies on adolescents have found that high-calorie, 100 percent fruit juices don't contribute to weight gain the way other caloric beverages do.

"While we didn't extrapolate these results out to adults, men can get one-third of their daily fruit servings from 100 percent juice as part of a healthy diet," says registered dietitian Carol O'Neil, Ph.D., the author of the study. Bottom line: One eight-ounce glass of 100 percent juice a day won't pad your gut.

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