Suspect you have a sluggish metabolism? You might have hypothyroidism, or an underactive thyroid gland, which afflicts about 25 percent of American women — many of whom don't know they have the condition, according to the American Association of Clinical Endocrinologists. "The thyroid gland controls your body's metabolism, so one of the first signs that it may be off is an inability to lose weight," explains Pamela Peeke, M.D., professor of medicine at the University of Maryland and author of Fight Fat After Forty. Your doctor can determine if you're suffering from hypothyroidism by running a blood test. If you do have an underactive thyroid, you'll be treated with a synthetic thyroid supplement, which you will need to take for the rest of your life (it will return your metabolism to normal, so it should be easier to drop unwanted pounds).
"When going out for fast food, I used to get the large-size value meal. Now, I satisfy a craving by ordering just one item: a small order of fries or a six-piece box of chicken nuggets. So far, I've shaved off 16 pounds in seven weeks, and I'm on track to being thinner than my high school self for my 10-year reunion later this year." —Miranda Jarrell, Birmingham, AL
"The answer is: it depends on your metabolism," Dr. Arad told POPSUGAR. Your metabolism relates to how your body produces energy from fats, sugars, and proteins as well as how it stores energy. Your metabolic rate, the number of calories you burn in a unit of time, provides insight on whether you have a fast or slow metabolism and how much energy you burn. To determine your metabolic rate, you'll need to get a resting metabolic rate (RMR) test (typically $250, but rates will vary), which are currently offered at specialized clinics like Fitnescity.
4. Eat more protein: Upping your protein is crucial for shedding fat. For starters, the macronutrient helps keep you full, preventing overeating and extraneous calories. And without adequate amounts of the macronutrient, muscle protein synthesis is diminished, your muscles can’t rebuild bigger and stronger, and your resting metabolism is lowered, says nutrition specialist and exercise physiologist, Marta Montenegro, CSCS, adjunct professor in Exercise & Sports Sciences at Florida International University. Plus, it gives your calorie burn a little boost since protein takes more energy for your body to process than carbs or fat.
You can get an estimate of how many calories you burn every day by using this calorie calculator. When you fill out the form, do your best to pick the level of activity that matches what you do on an average day. If you say you're more active than you really are, you'll end up with a lot more calories than your body needs, and you'll start gaining weight. For the moment, choose "maintenance" as your goal.
If you’re actively watching your weight this season, know this: Research from the University of Chicago found that dieters lost 55% less fat when they slept for 5½ hours than when they slept for 8½ hours. To settle into slumber more easily, avoid lit screens, food and, yes, booze for a full two hours before bed, and fill your plate with foods that help you fall asleep earlier in the night (think cherries, jasmine rice, and bananas).
At its core, burning fat comes down to the process of lipolysis—the breaking down of fat lipids, explains Seedman. This happens in the mitochondria of the muscles, or the powerhouses of the cells, responsible for generating the energy our cells need to do their jobs. Exercise has been shown to improve mitochondria function, which then promotes fat breakdown, Seedman adds. Plus, working out helps regulate pretty much all the hormones that optimize fat loss.