Most people cutting fat should eat 300 to 500 calories below their maintenance level, which typically lands somewhere between 1,500 and 2,500 calories per day depending on your size, age, sex, and activity level. There’s no single number that works for everyone, but the math to find yours is straightforward.
How to Find Your Maintenance Calories
Before you can set a deficit, you need to know how many calories your body burns in a normal day. This number, often called your total daily energy expenditure (TDEE), starts with your resting metabolic rate and scales up based on how active you are.
The most widely used formula for resting metabolic rate is the Mifflin-St Jeor equation:
- Men: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Women: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
That gives you the calories your body burns at complete rest. To account for daily movement, multiply by an activity factor: 1.2 for sedentary (desk job, little exercise), 1.375 for lightly active (1 to 3 workouts per week), 1.55 for moderately active (3 to 5 workouts), 1.725 for very active (hard training most days), or 1.9 for extremely active (physical job plus intense training).
For example, a 30-year-old man who weighs 185 pounds (84 kg), stands 5’10” (178 cm), and lifts weights four days a week would have a resting rate of about 1,782 calories. Multiply by 1.55 for moderate activity and his estimated maintenance is roughly 2,762 calories per day.
How Big Your Deficit Should Be
A daily deficit of 300 to 500 calories is the range that supports steady fat loss without excessive muscle loss or energy crashes. For most people, that translates to losing about 0.5 to 1 pound per week. The CDC notes that people who lose at this gradual pace of 1 to 2 pounds per week are more likely to keep the weight off than those who cut faster.
Using the example above, that 2,762-calorie maintainer would set his cutting calories at roughly 2,250 to 2,450 per day. Someone maintaining at 2,000 calories would aim for about 1,500 to 1,700.
You can go more aggressive, but there are real tradeoffs. Larger deficits accelerate muscle loss, tank your energy in the gym, and trigger stronger hunger signals. In the first phase of a steep cut, much of the initial weight loss comes from glycogen (stored carbohydrate) and the water bound to it, not actual fat. That early dramatic drop on the scale can be misleading and often reverses quickly once you eat normally again.
Why Protein Matters More During a Cut
When you’re in a deficit, your body doesn’t just pull energy from fat. It also breaks down muscle tissue for fuel, especially if protein intake is too low. Eating enough protein is the single most effective way to limit that muscle loss while cutting.
For athletes and people who train regularly, aiming for 1 to 1.5 grams of protein per pound of your goal body weight provides enough raw material to preserve lean mass. If you currently weigh 185 pounds and want to get down to 170, that’s 170 to 255 grams of protein per day. For people who are less active, keeping protein at 25 to 35% of total calories is a reasonable target.
Your body can only absorb and use about 25 to 35 grams of protein at a time, so spreading your intake across four or five meals works better than loading it all into one or two sittings. Protein also keeps you fuller for longer, which makes sticking to a deficit considerably easier.
What Happens to Your Metabolism on a Cut
Your body doesn’t passively accept a calorie deficit. It fights back. When you restrict calories for weeks or months, your metabolism slows down more than the simple loss of body weight would predict. Researchers call this metabolic adaptation, and it’s a real, measurable phenomenon.
In long-term studies, metabolic rate during sleep dropped by about 5 to 8% beyond what body composition changes alone could explain, and the effect was nearly double during normal waking activity, reaching 9 to 13% at various time points over two years. This happens because your body dials down several systems at once: thyroid hormone output decreases, leptin (a hormone that regulates hunger and energy expenditure) drops as you lose fat, and insulin signaling shifts to conserve energy.
One of the sneakiest effects is the drop in non-exercise activity thermogenesis, or NEAT. This is all the movement you do that isn’t formal exercise: fidgeting, walking around the house, taking the stairs, gesturing while you talk. During a cut, your body unconsciously reduces this movement to conserve energy. You sit more, move less between sets, take the elevator without thinking about it. This invisible reduction in calorie burn is a major contributor to weight loss plateaus.
You can counteract some of this by deliberately keeping your step count up, using a standing desk, and generally staying aware of how much you move outside the gym.
Using Refeed Days to Stay on Track
Eating at a deficit seven days a week for months is hard on both your body and your motivation. Scheduled refeed days, where you temporarily raise calories back to maintenance or slightly above, can help on both fronts.
Refeeds work by briefly restoring glycogen stores and nudging leptin and cortisol levels back toward normal. This gives your muscles more fuel for training and provides a psychological break from restriction. In one study of resistance-trained men and women, a group that alternated between five days of energy restriction and two days of refeeding retained significantly more muscle than a group that stayed in a continuous deficit over seven weeks.
A refeed is not a cheat day. It’s a controlled increase in calories, primarily from carbohydrates, up to your maintenance level. You’re not eating whatever you want in unlimited quantities. One or two refeed days per week is a common approach, though there’s no single proven protocol for frequency. If your cut is moderate (300 to 500 calorie deficit), one refeed day per week or every two weeks is typically enough. More aggressive cuts may benefit from more frequent refeeds.
Signs Your Deficit Is Too Aggressive
Some discomfort during a cut is normal. Feeling genuinely hungry before meals, having slightly less energy, and thinking about food more often are all expected. But certain signals mean you’ve pushed the deficit too far or sustained it too long.
Watch for persistent fatigue that doesn’t improve with sleep, noticeable strength loss in the gym over multiple sessions, irritability or brain fog that affects your daily life, feeling cold all the time (a sign of reduced thyroid output), and a complete stall in weight loss despite consistent adherence. That last one is often the plateau caused by metabolic adaptation and reduced NEAT catching up to your deficit.
If you hit a true plateau, the fix is usually not to cut calories further. Instead, try adding a full diet break of one to two weeks at maintenance calories, increasing your daily movement outside the gym, or reassessing your tracking to make sure portion sizes haven’t crept up.
Putting Your Numbers Together
Here’s the practical sequence. Calculate your resting metabolic rate using the Mifflin-St Jeor formula. Multiply by your honest activity level. Subtract 300 to 500 calories from that number. Set protein at 1 to 1.5 grams per pound of your goal weight if you’re training, and fill the remaining calories with carbohydrates and fats based on your preference and energy needs.
Track your weight over two to three weeks before making adjustments. Daily fluctuations from water, sodium, and digestion can swing the scale by several pounds, so weekly averages are far more reliable. If you’re losing 0.5 to 1 pound per week on average, you’re in the right zone. If the scale isn’t moving after three consistent weeks, drop another 100 to 150 calories or add more daily movement. If you’re losing faster than 1.5 pounds per week and you’re not significantly overweight, you’re likely losing muscle along with the fat and should ease up.