How to lose body fat (and keep your muscle)

Fat loss starts with a small deficit

Your body stores extra energy as fat. To use that fat, you need to take in a little less energy than you burn each day. That gap is your calorie deficit.

A deficit of about 300 to 500 calories a day is a good starting point for most adults. It's big enough to see progress and small enough to keep up. Find your daily burn with the TDEE calculator, then set a target with the calorie deficit calculator.

Protect your muscle while you lose

When you eat less, your body can break down muscle as well as fat. Two habits push the loss toward fat:

• Enough protein. A common target while losing weight is 1.2 to 1.6 grams per kilogram of body weight a day. Get your number with the protein floor calculator.
• Strength training. The CDC recommends muscle-strengthening work at least 2 days a week. Start with simple moves: squats, pushes, pulls and carries. See strength training for beginners.

Move more in ordinary ways

Cardio helps, but everyday movement often matters more over a week. Walking, taking stairs and standing breaks all add up. Adults are advised to get at least 150 minutes of moderate activity a week. Turn your step count into miles and calories with the steps to miles calculator.

Why you can't spot reduce

Crunches build your stomach muscles, but they don't burn the fat sitting on top of them. Your body decides where fat comes off first, mostly based on genetics, age and sex. Keep the deficit going and stubborn areas usually shrink last, but they do shrink.

Measure fat, not just weight

Body fat can drop while the scale stalls, especially if you're new to lifting. Track a few numbers every 2 to 4 weeks:

• Waist at the belly button, measured the same way each time
• An estimate from the body fat calculator
• Photos and how your clothes fit

Many people find a realistic pace is about 0.5 to 1 percent of body weight a week. Faster than that usually costs more muscle.

A week that burns fat

Nothing here is extreme. Fat loss comes from doing ordinary things most days for months.

Why progress slows, and what to do

As you get lighter, you burn a little less each day, so a deficit that worked at the start gets smaller over time. Every 10 to 15 pounds lost, recheck your numbers with the TDEE calculator and adjust.

Stalls of 2 to 3 weeks are normal, often from water shifts. If the trend stays flat for a month, tighten portions slightly or add a daily walk. See breaking a weight-loss plateau.

A worked example with numbers

Take a 40-year-old woman who is 5 ft 5 in, weighs 190 pounds and is lightly active. Her daily burn is roughly 2,100 calories. You can check a similar estimate on the TDEE page for a 190-lb woman.

A 400-calorie deficit puts her target near 1,700 calories a day, well above the 1,200 floor. Her protein goal at 1.2 to 1.6 g/kg (about 86 kg) is roughly 105 to 140 grams. The 190-lb protein page shows the same range.

At that pace, she might lose around 0.75 to 1 pound a week at first. That's slow enough to protect muscle and fast enough to see her waist change within a month or two.

Common fat-loss mistakes

• Cutting too hard. Big deficits raise hunger and muscle loss, and they're hard to keep.
• Skipping strength work. Cardio alone lets more of the loss come from muscle.
• Weekend drift. Two loose days can erase much of a weekday deficit.
• Judging by one weigh-in. Daily weight can swing 1 to 4 pounds with water and salt. Log weigh-ins in the weigh-in tracker and watch the weekly average.

Small wins count. A slightly smaller deficit you keep for 6 months beats a perfect one you quit in 3 weeks.

When medical help makes sense

If you've tried for months without progress, or you have a condition like type 2 diabetes or sleep apnea, a clinician can check for causes and talk through options, including prescription medicines. Learn who qualifies for a GLP-1 and how muscle loss on a GLP-1 works.