A daily calorie deficit of 500 to 750 calories is the standard recommendation from most obesity guidelines, and it typically produces about half a pound to one pound of weight loss per week. That range hits the sweet spot between meaningful progress and sustainability, which is why it shows up so consistently across health organizations. But the right deficit for you depends on your starting point, your activity level, and how much muscle you want to hold onto.
What a 500 to 750 Calorie Deficit Looks Like
A calorie deficit means consuming fewer calories than your body burns in a day. If your body uses 2,400 calories daily and you eat 1,900, you’re in a 500-calorie deficit. Maintained over a week, that adds up to a 3,500-calorie shortfall, which roughly translates to about half a pound to one pound lost.
The UK’s National Institute for Health and Care Excellence recommends a deficit of 500 to 600 calories per day, producing around 0.5 to 1 kilogram (roughly 1 to 2 pounds) of weight loss per week. A low-calorie diet following this approach generally lands between 1,000 and 1,500 calories per day for most people, though the exact number varies based on how much energy you burn.
How to Estimate Your Starting Number
Before you can create a deficit, you need a rough estimate of how many calories your body burns at rest. Several formulas exist for this, but the Mifflin-St Jeor equation is the most accurate for the widest range of people. A systematic review comparing the most common formulas found it predicted resting metabolic rate within 10% of the actual measured value more often than the older Harris-Benedict equation or others used in clinical practice.
You can find Mifflin-St Jeor calculators online. They use your age, sex, height, and weight to estimate resting metabolism, then multiply by an activity factor to approximate your total daily energy expenditure. That final number is your maintenance calories. Subtract 500 to 750 from it, and you have your target intake. These calculators aren’t perfect, especially for older adults and certain ethnic groups where validation data is limited, but they’re a reasonable starting point.
Why Aggressive Deficits Backfire
Cutting 1,000 or more calories per day might seem like it would speed things up, and in the short term it does. But aggressive deficits carry real costs. Your body responds to severe restriction by slowing its metabolism, a process researchers call metabolic adaptation. Your resting calorie burn drops by more than you’d expect from the weight loss alone, making continued progress harder and regain more likely.
A study following contestants from “The Biggest Loser” illustrates this dramatically. After the competition, participants had lost an average of 58 kilograms, and their resting metabolic rate had dropped by about 610 calories per day. Six years later, even though they had regained most of the weight, their metabolism was still suppressed by roughly 700 calories per day compared to baseline. The metabolic adaptation itself, the amount of slowdown beyond what body composition changes would predict, was about 499 calories per day at the six-year mark. Contestants who had lost the most weight experienced the greatest ongoing metabolic suppression.
This doesn’t mean all dieting ruins your metabolism. But it does show that extreme approaches create a disproportionate metabolic penalty that persists for years. Moderate deficits produce less dramatic adaptation and consistently lead to better long-term weight maintenance.
Minimum Calorie Floors
Regardless of how large your deficit needs to be, there are floors you shouldn’t drop below. Women should generally consume no fewer than 1,200 calories per day, and men no fewer than 1,500 calories per day. Going below these thresholds makes it very difficult to get adequate vitamins, minerals, and other nutrients from food alone. It also triggers the kind of metabolic slowdown that makes weight loss paradoxically harder over time.
The Role of Movement and Daily Activity
You can create a calorie deficit through eating less, moving more, or both. But how you move matters in ways that aren’t immediately obvious.
Structured exercise (running, lifting, cycling) accounts for a relatively small share of daily calorie burn for most people, typically 15 to 30% of total expenditure even in people who train regularly. The bigger contributor to your daily activity burn is non-exercise movement: walking to the car, fidgeting, standing, doing chores. This type of everyday movement can account for anywhere from 6 to 10% of total energy expenditure in sedentary people up to 50% or more in highly active individuals. It’s also the most variable component of your calorie burn from day to day.
Here’s the catch: when you combine a calorie deficit with exercise, the intensity of your workouts matters for total energy expenditure. Research shows that when people diet without exercising, their everyday non-exercise movement drops by about 150 calories per day, roughly a 27% decline. Adding moderate exercise to a diet preserves that everyday movement. But if the exercise program is too intense during caloric restriction, it can actually suppress daily non-exercise movement rather than protect it, partially canceling out the calories burned during workouts. Older adults and men appear more susceptible to this compensation effect. The practical takeaway: pair your calorie deficit with moderate, consistent exercise rather than punishing workouts.
Protecting Muscle During a Deficit
When you lose weight, some of that loss comes from fat and some from muscle. Losing too much muscle lowers your resting metabolic rate, reduces strength, and makes weight regain easier. Protein intake is the most important dietary lever for minimizing muscle loss.
A study in resistance-trained athletes compared two groups eating 60% of their usual calories for two weeks. One group ate about 1.0 gram of protein per kilogram of body weight (roughly 15% of calories from protein), while the other ate about 2.3 grams per kilogram (35% of calories from protein). The higher-protein group lost 1.5 kilograms total and only 0.3 kilograms of lean mass. The lower-protein group lost 3.0 kilograms total and 1.6 kilograms of lean mass, more than five times as much muscle.
For practical purposes, if you’re in a calorie deficit and want to preserve muscle, aim for roughly 1.6 to 2.4 grams of protein per kilogram of body weight daily. For a 75-kilogram (165-pound) person, that’s about 120 to 180 grams of protein per day. Combining higher protein intake with some form of resistance training gives you the best shot at losing fat while keeping muscle.
Putting It Together
Start by estimating your total daily calorie burn using a Mifflin-St Jeor calculator. Subtract 500 to 750 calories to set your daily intake target. Make sure that target doesn’t fall below 1,200 calories for women or 1,500 for men. Keep protein high, around 1.6 to 2.4 grams per kilogram of body weight. Add moderate exercise to preserve your everyday movement patterns and protect muscle mass.
Expect to lose about half a pound to one pound per week at a 500-calorie deficit, or up to 1.5 pounds at a 750-calorie deficit. Weight loss won’t be perfectly linear. Water retention, hormonal shifts, and digestive timing all cause the scale to bounce around day to day. Weekly averages over several weeks give you a much clearer picture of real progress than any single weigh-in.