This Is Exactly How to Eat and Work Out to Lose Fat Faster — and Do It Safely

You can't choose where you lose fat first (like from your thighs or belly), but if you want to shed it quickly, "you must expend more calories than you ingest," Charles Seltzer, MD, DABOM, CEP, a board-certified bariatric physician based in Philadelphia, PA, told POPSUGAR. "The more rapidly you would like to lose fat, the larger the calorie deficit must be." But if you read that as permission to radically cut calories, know this: overhauling your diet alone will only set you up for failure, as you're more likely to lose muscle that way than fat. Here's how to safely speed up fat loss with diet and exercise, without running the risk that you'll gain it back down the road.

What to Eat to Lose Fat Quickly

"The fastest way to lose fat is to remove sugar and reduce simple carbohydrates like bread, pasta, potatoes, and rice," Wendy Scinta, MD, MS, president of the Obesity Medicine Association and a board-certified bariatric physician based in Fayetteville, NY, told POPSUGAR. "If you want it to be really fast, try cutting your net carbohydrates down to 20 grams." Net carbs are calculated by subtracting fiber from total carbs. For context, 20 grams of net carbs falls in the range of the very low-carb keto diet. "If you choose this, you may need to cut your exercise back a bit until your body can become keto-adaptive (meaning it's used to running on ketone bodies instead of glucose)," Dr. Scinta explained. "Take in at least half your weight in grams of protein to preserve muscle mass."

Just keep in mind that if you suddenly switch to a diet like keto when you're accustomed to eating junk food, you may struggle to implement such a drastic change. "From a lifestyle standpoint, the more you change at once, the less likely it is to stick over the long run," Dr. Seltzer said. If you want to clean up your diet, start slow by eating more plant-based foods, then shift over to a more low-carb diet if that's what you want to do.

How to Exercise For Fat Loss

While diet is most effective at speeding up fat loss, exercise is essential. Both doctors recommend incorporating high-intensity interval training (HIIT) to increase the rate of fat burning during and after your workout. "HIIT can also help protect your muscle mass while you are in a calorie deficit," Dr. Seltzer said. During any other workout, aim to reach 70 percent of your maximum heart rate, known as the fat-burning zone. "The formula for maximum heart rate is 220 minus your age," Dr. Scinta explained. "To find your fat-burning zone, you then multiply this by 0.7." A 22-year-old's maximum heart rate would be 198, which means she should aim to reach 139 during her workouts.

To help maintain muscle mass after tough workouts and keep your metabolism stable — which is crucial for keeping the weight off — aim for at least 1 gram of protein per kilogram of body weight, Dr. Scinta added. But of course, the best way to ensure long-term success is to listen to your body and lose weight at its pace. "Being patient and not taking drastic measures in the first place is the best play," Dr. Seltzer said.