A daily calorie deficit of 500 calories is the most widely recommended starting point for steady weight loss, translating to roughly half a pound to one pound lost per week. But the right deficit for you depends on how much you currently eat, how active you are, and how much weight you have to lose. Here’s how to find your number and stick with it.
How a Calorie Deficit Works
Your body burns a set amount of energy every day just to keep you alive and moving. This is your total daily energy expenditure, or TDEE. It has three main components: your resting metabolic rate (the calories your body burns doing nothing but breathing and pumping blood), the calories burned through physical activity, and about 10 percent of your daily calories spent digesting food. When you consistently eat fewer calories than your TDEE, your body pulls the difference from stored energy, primarily fat, and you lose weight.
The 500-Calorie Starting Point
The CDC recommends losing 1 to 2 pounds per week as a pace that people are more likely to maintain long term. Cutting about 500 calories per day from your usual intake puts you in that range, and it’s the figure Mayo Clinic and most major health organizations point to. A 1,000-calorie daily deficit would push you closer to 2 pounds per week, but that’s aggressive and harder to sustain, especially for smaller or less active people.
The problem with a flat 500-calorie cut is that it doesn’t account for body size. If you’re a 200-pound person eating 2,800 calories a day, dropping to 2,300 is a modest 18 percent reduction. If you’re a 130-pound person eating 1,800 calories, that same 500-calorie cut drops you to 1,300, which is a nearly 28 percent reduction and much harder to live with. A percentage-based approach, aiming for a 15 to 25 percent reduction from your TDEE, often works better because it scales to your body.
How to Estimate Your TDEE
To know your deficit, you first need a reasonable estimate of what you’re burning. The simplest method is to multiply your resting metabolic rate by an activity factor. Online TDEE calculators do this for you using your age, sex, height, weight, and general activity level. They aren’t perfectly accurate, but they give you a useful starting point.
For example, a moderately active 35-year-old woman who weighs 160 pounds might have a TDEE around 2,100 calories. A 500-calorie deficit would put her daily target at 1,600. A moderately active 35-year-old man at 200 pounds might burn closer to 2,700 calories, making his target around 2,200. These are estimates. The real test is what happens on the scale over two to four weeks.
Diet Matters More Than Exercise for the Deficit
You can create a calorie deficit by eating less, moving more, or both. In practice, food restriction is far more efficient. As Mayo Clinic puts it, you’d have to do huge amounts of physical activity to match the energy deficit you can achieve simply by cutting down on calories. Running for 30 minutes might burn 300 calories. Skipping a large muffin does the same thing with zero effort.
That said, exercise plays a different role. Diet is more effective for losing weight, but physical activity is what helps you keep it off. Exercise also preserves muscle, improves mood, and offsets some of the metabolic slowdown that comes with eating less. The best approach combines a moderate dietary deficit with regular movement rather than relying on one or the other alone.
Why Your Deficit Stops Working
Nearly everyone hits a plateau, and it’s not because of willpower. As you lose weight, your body burns fewer calories. You’re literally carrying less mass, so every movement costs less energy. You also lose some muscle along with fat, and muscle is more metabolically active than fat tissue. Your resting metabolic rate drops, which means the deficit that worked at 200 pounds may produce no loss at 175 pounds.
There’s also a water-weight effect that makes early progress misleading. During the first few weeks of a calorie deficit, your body burns through its glycogen stores, a form of stored carbohydrate in your muscles and liver. Glycogen holds onto water, so when it’s used up, you shed water weight quickly. That initial rapid drop slows once glycogen stores are depleted, and the pace shifts to actual fat loss, which is slower and steadier.
When you hit a plateau, the fix is recalculating. Your TDEE at your new, lower weight is different than it was when you started. You either need to eat slightly less, move slightly more, or accept a slower rate of loss.
Protecting Muscle During a Deficit
Losing weight without preserving muscle leaves you lighter but weaker, and it accelerates the metabolic slowdown that causes plateaus. Protein intake is the single biggest dietary lever for holding onto muscle while you lose fat.
Research consistently shows that higher protein intakes, in the range of 1.2 to 1.6 grams per kilogram of body weight per day, preserve lean mass and improve body composition during weight loss compared to the standard recommendation of 0.8 grams per kilogram. For a 170-pound person, that means roughly 90 to 120 grams of protein daily. Intakes above 1.3 grams per kilogram are associated with actual increases in muscle mass, while dropping below 1.0 gram per kilogram raises the risk of muscle loss.
In practical terms, this means building each meal around a protein source: eggs, Greek yogurt, chicken, fish, tofu, legumes. Resistance training two to three times per week amplifies the effect, giving your muscles a reason to stick around even when calories are low.
How to Set Your Personal Target
Start by estimating your TDEE with an online calculator. Subtract 500 calories, or aim for a 20 percent reduction, whichever feels more manageable. Track your weight weekly (not daily, since water fluctuations can mask real trends) for three to four weeks. If you’re losing about a pound a week, your deficit is working. If the scale isn’t moving, you’re either eating more than you think or your TDEE estimate was too high. Adjust by 100 to 200 calories and reassess.
A few guardrails to keep in mind. Setting unrealistic goals, like losing 20 pounds in two weeks, leads to frustration and burnout. Most women should avoid going below about 1,200 calories per day, and most men below 1,500, without medical supervision. If your calculated deficit pushes you below those floors, a smaller deficit combined with more physical activity is a safer path. Losing weight a little more slowly and keeping it off beats losing it fast and regaining it within a year.