500 Calorie Deficit

On this page

1. Where “500 calories a pound” comes from
2. What you can really expect
3. When 500 is too much
4. When 500 is too little
5. A better rule: a percentage of TDEE
6. Ways to create a 500 kcal deficit
7. What 500 kcal looks like in food
8. How long to test it
9. When to recalculate
10. Don’t expect a pound every single week
11. 500 calorie deficit questions

Where “500 calories a pound” comes from

In 1958, the physician Max Wishnofsky estimated that a pound of body weight lost or gained holds about 3,500 kcal. Divide by seven days and you get 500 kcal a day for a pound a week. In metric terms, the rule is about 7,700 kcal per kilo, so a 500 kcal deficit is about 0.45 kg a week.

As a starting estimate, it is reasonable. The problem is that people treat it as a promise: eat 500 less, lose a pound every week until you reach your goal. Bodies don’t work that way, for three reasons.

What you can really expect

1. The first week is faster. When you eat less, especially less carbohydrate, your muscles store less glycogen, and each gram of glycogen holds roughly three to four grams of water. There is also less food in your gut. A drop of 1 to 2 kg (2 to 4 lb) in week one is common, and most of it isn’t fat.

2. The middle is close to the rule. From week two or three onwards, loss usually settles near the predicted 0.45 kg a week, with ups and downs from water.

3. The later months are slower. As you lose weight, your TDEE falls, so the same intake gives a smaller deficit. Many people also move less without noticing while dieting. Here is a simple model for a 35-year-old woman, 168 cm (5′6″) and 75 kg (165 lb), lightly active, who starts with a TDEE of 2,013 kcal and eats 1,513 kcal every day:

The model only accounts for her shrinking body; it doesn’t include water swings or any extra adaptation, both of which add noise. The lesson is simple: a fixed 500 kcal cut slows down by itself. Recalculating every 4 to 5 kg keeps the deficit near 500.

When 500 is too much

A fixed deficit hits small, less active people hardest. As a share of TDEE:

It is also too much if you are already lean, if it pushes you below about 1,200 kcal (women) or 1,500 kcal (men) a day, or if it means losing more than about 1% of your body weight a week. In those cases, use 250 to 350 kcal, or 15% of your TDEE.

When 500 is too little

For a large or very active person with a TDEE of 3,000 to 3,500 kcal, 500 kcal is a modest 14 to 17% deficit. That isn’t a problem; slow loss is easy to sustain. But if you have a lot to lose and want to move faster, a 20 to 25% deficit is reasonable for a while, as long as the pace stays under about 1% of body weight a week.

A better rule: a percentage of TDEE

Instead of a fixed 500, take 15 to 25% off your TDEE. It gives everyone a similar level of effort. The calorie deficit calculator works the other way, from a pace you choose, and warns you when a plan is too steep. Our calorie deficit calculator guide explains both methods.

Ways to create a 500 kcal deficit

• Food only: eat 500 kcal below your TDEE. Simple to track.
• Food and walking: eat about 300 to 350 kcal less and add 5,000 to 6,000 daily steps, worth roughly 150 to 200 kcal for many adults. You eat more and protect your daily movement.
• Food and training: eat about 400 kcal less and add regular workouts. Strength training also helps you keep muscle.

Whichever you choose, count the activity in your activity level or your plan, not as bonus calories to eat back.

What 500 kcal looks like in food

A daily deficit of 500 kcal sounds abstract. In real food it is often a few habits rather than a whole meal:

• a large flavoured coffee and a pastry from the café (often 500 kcal or more together);
• two tablespoons of oil in cooking plus a can of sugary drink (about 380 kcal) plus a biscuit or two;
• a second helping of rice or pasta at dinner and a chocolate bar in the afternoon;
• two pints of beer or two large glasses of wine (roughly 400 to 500 kcal).

Finding two or three of these in your normal week, and swapping them for lower-calorie versions, is often easier than cutting portions across the board. Brands and recipes vary, so check labels for the things you eat most.

How long to test it

Give it three to four weeks. Ignore the first week’s drop, then compare weekly average weights from week two onwards. If you are losing roughly 0.3 to 0.6 kg (¾ to 1¼ lb) a week, the deficit is about right. If nothing has moved after three weeks of careful logging, your TDEE estimate was probably too high: reduce by 100 to 150 kcal or add steps. The adaptive TDEE calculator works out your real TDEE from your data.

When to recalculate

After every 4 to 5 kg (10 lb) of loss, or when your weekly average has been flat for three weeks despite accurate logging. Recalculate your TDEE at your new weight and set a fresh 500 kcal, or 20%, below it. Our guide on recalculating TDEE during weight loss has a step-by-step method.

Don’t expect a pound every single week

Even when your average is spot on, individual weeks vary. A salty meal, a hard workout, a poor night’s sleep or the days before a period can hide a week’s fat loss behind a kilo of water. Look at four-week trends. If the line is going down at roughly the planned pace, the deficit is working, whatever this Tuesday says.

500 calorie deficit questions

Does a 500 calorie deficit always mean 1 lb a week?

No. It is close in the first couple of months, faster in week one because of water, and slower later as your TDEE falls. Over six months, expect noticeably less than a pound a week on average unless you recalculate.

Is a 500 calorie deficit too much?

For people whose TDEE is under about 2,000 kcal, it often is: it is 25% or more of their daily burn and may push intake below 1,200 kcal. For people with higher TDEEs it is moderate.

Should I use a 250 calorie deficit instead?

If you are small, lean, close to your goal or have a low TDEE, yes, 250 to 350 kcal is a sensible choice. Loss is slower, about 0.25 kg (½ lb) a week, but easier to sustain.

How long should I test a 500 calorie deficit?

Three to four weeks, ignoring the first week. Judge it by your weekly average weight, not single weigh-ins.

When should I recalculate my deficit?

After every 4 to 5 kg (10 lb) of weight lost, or after a three-week stall with accurate logging.

How much weight will I lose in a month with a 500 calorie deficit?

Roughly 1.5 to 2 kg (3 to 4.5 lb) in the first month, including some water. In later months, often a little less, unless you recalculate.

Is a 500 calorie deficit right for women?

It depends on your TDEE, not your sex. Many women have a TDEE under 2,000 kcal, where 500 kcal is 25% or more. A 15 to 20% deficit, often 300 to 400 kcal, is usually a better fit.

Is a 500 calorie deficit enough for men?

For many men it is a moderate 15 to 20% of TDEE and works well. Larger, more active men can go a little bigger if they have a lot to lose, keeping the pace under about 1% of body weight a week.

Can I split the 500 calories between diet and exercise?

Yes. For example, eat 300 kcal less and walk an extra 5,000 to 6,000 steps a day. Just don’t also eat back the exercise calories.

Sources

1. Wishnofsky M. Caloric equivalents of gained or lost weight. Am J Clin Nutr. 1958;6(5):542-546. doi.org/10.1093/ajcn/6.5.542
2. Hall KD. What is the required energy deficit per unit weight loss? Int J Obes (Lond). 2008;32(3):573-576. doi.org/10.1038/sj.ijo.0803720
3. Thomas DM, Martin CK, Lettieri S, et al. Can a weight loss of one pound a week be achieved with a 3500-kcal deficit? Commentary on a commonly accepted rule. Int J Obes (Lond). 2013;37(12):1611-1613. doi.org/10.1038/ijo.2013.51
4. Hall KD, Sacks G, Chandramohan D, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet. 2011;378(9793):826-837. doi.org/10.1016/S0140-6736(11)60812-X
5. Kreitzman SN, Coxon AY, Szaz KF. Glycogen storage: illusions of easy weight loss, excessive weight regain, and distortions in estimates of body composition. Am J Clin Nutr. 1992;56(1 Suppl):292S-293S. doi.org/10.1093/ajcn/56.1.292S
6. Rosenbaum M, Leibel RL. Adaptive thermogenesis in humans. Int J Obes (Lond). 2010;34(Suppl 1):S47-S55. doi.org/10.1038/ijo.2010.184