When it comes to health topics, has there ever been a horse more thoroughly beaten to death than dieting? An Amazon book search for “weight loss” yields 129,702 titles on the subject—and you can bet they all promise they’ll get you an eternal six-pack, whether it’s via juice fasting, the South Beach Diet, veganism, Paleo, or eating for your blood type.
Unfortunately, the vast majority of these claims—even the old chestnut that you if you eat five small meals a day it’ll “rev your metabolism”—aren’t actually based on a shred of science.
Thankfully, there are some tried-and-true methods for losing your gut—and keeping it off—that can’t be discredited by any new trend. Bearing in mind everything we know right now about the science of staying slim, here’s everything you should be doing, from training to nutrition, to get a body that looks great and can be maintained for the long run—by real people in the real world.
1. Eat whole foods as often as possible
Everybody hits up Chipotle once in a while. But if you know what to order when you go out, you can minimize the damage and still enjoy somebody else making your food for a change.
Look at what’s on the menu and choose the foods that are as close to what’s available in nature as possible. Meat, vegetables, and whole fruits are all A-OK; tortilla shells, burger buns, pasta, and cheese are not. Swap out soda for seltzer water with a lemon wedge. Instead of having an energy bar to reverse your afternoon crash, have an apple or some almonds.
Get in the habit of avoiding foods that come with bar codes and you’ll save calories every time.
2. Control your portions
Even when you eat healthy, there’s still the danger of gaining weight if you’re prone to overeating. After all, chicken breasts and fruits still have calories, and those calories add up.
Avoid buffets and similar all-you-can-eat affairs, and remember these components of a healthy meal: Every plate you serve yourself should include a portion of protein (lean meat or fish) that’s about the size and thickness of your palm and a fist-size serving of clean carbs (potatoes or rice are the best). Then fill up the rest of the plate with vegetables.
Any other foods you really crave (such as fat-heavy foods and some of the more high-sugar fruits) should be eaten more sporadically.
3. Don’t fear fat
The “low-fat” era is over—we now know that processed carbs like white bread, pasta, and sugary cereals contribute more to obesity than the fat that comes from whole foods. The main reason: Fat is filling. Processed foods are easy to overeat. “The key is to eat food that makes it really difficult to overeat,” says visiting MIT scientist and InsideTracker founder Gil Blander, Ph.D. Don’t be afraid to use a tablespoon of coconut oil when cooking or to add avocado to a salad.
Nuts and seeds make great snacks, too. Remember Tactic 2, though: Fat is still higher in calories than any other nutrient, so keep your servings small (that is, don’t eat a bag of almonds in a sitting or pour a cup of olive oil on your salad). Fat may be filling, but don’t think you’re somehow immune to overeating it.
4. Practice the 80/20 rule
No one can eat perfectly 100% of the time, and that’s where cheat meals fit into the picture. Some call it the 80/20 rule: Eat healthy 80% of the time, and the occasional slice of pizza or bowl of ice cream (or both in one night) won’t do you in. Or plan on having one cheat meal a week. It’s good to reward yourself—it stiffens your resolve to continue with the diet.
5. Track the numbers that matter
Get a scale that measures not just weight—studies show that if you weigh yourself daily you’ll keep the pounds off—but also body composition. Because working out adds muscle, which is denser than fat, your weight may go up (or plateau) for a bit. But if your body-fat percentage is dropping, you know you’re progressing.
6. Experiment on yourself
Some people can’t eat many carbs without putting on weight, and others can’t handle much fat. “Understanding a person’s individual biochemistry and making personalized recommendations is the future of medicine,” says Blander. The point is: Don’t settle for one-size-fits-all solutions. If one eating plan doesn’t suit you, try another, avoiding extremes. And if all else fails, go back to Tactic 1: Eating only whole, natural, unprocessed foods has never made anyone fatter.
7. Master HIIT training
To get and stay lean, weight training (which you already do) and high-intensity interval training must be a part of your life.
Interval workouts are super-effective at revving up your metabolism. The premise: You work at the highest intensity you can for 10–30 seconds, then rest or go at an easy pace for the same amount of time. Repeat for 15–20 minutes.
Examples include sprinting up a hill, then walking down; sprinting on an exercise bike, then doing light pedaling; or doing a pre-set circuit of bodyweight exercises like jumping jacks, mountain climbers, and burpees.
“HIIT boosts your metabolism in a way walking just can’t,” says Blander. Do it twice a week on nonconsecutive days.
8. Don’t skimp on sleep
Sleep deprivation—missing out on even 30 minutes a night—can raise your risk of obesity as well as diabetes, the Endocrine Society says. Why? Because it decreases the satiation hormone leptin, increases the hunger hormone ghrelin, and lessens your body’s sensitivity to insulin, which makes it harder to process the carbs you eat. Poor sleep literally rewires your appetite and reduces your willpower. “The science is clear,” adds Blander, “when you don’t sleep well you eat more."