How Many Calories Should I Eat a Day to Lose Weight?

Because so much of weight-loss is accomplished in the kitchen, discovering what your caloric intake should be  is probably the most important thing you can know on your quest to lose weight.

While there are a slew of diets out there, at the end of the day losing weight comes down to expending more calories than you take in – not some complicated eating scheme.

Caloric intake will vary per person and is based on a few important pieces of information: your gender, age, current weight, activity level (ie, your caloric expenditure or how many calories you burn daily), and the rate at which you would like to lose weight.

When you have these figures in mind, then it’s time to find out your basal metabolic rate (BMR) which is physiology geek-speak for how many calories you would burn daily without any activity – or if you were to basically spend the day in bed watching chick-flicks…not that I’ve ever done that ;-). (Read more about BMR.)

Basal Metabolic Rate

So now that you know a new fancy fitness-term, it’s time to show you the formula. It goes a little something like this…

English BMR Formula
Women: BMR = 655 + ( 4.35 x weight in pounds ) + ( 4.7 x height in inches ) – ( 4.7 x age in years ) Men: BMR = 66 + ( 6.23 x weight in pounds ) + ( 12.7 x height in inches ) – ( 6.8 x age in year )
Metric BMR Formula
Women: BMR = 655 + ( 9.6 x weight in kilos ) + ( 1.8 x height in cm ) – ( 4.7 x age in years ) Men: BMR = 66 + ( 13.7 x weight in kilos ) + ( 5 x height in cm ) – ( 6.8 x age in years )

Don’t worry about having a high-school math class flashback, I’ve found a groovy little tool to help you find out your basal metabolic rate, and from that you can derive how many calories you should be eating a day to lose weight. In fact, the tool even makes a couple suggestions for caloric intake for you depending on what they call “Fat Loss” and “Extreme Fat Loss.” But let me get to that below so you know what it actually means regarding your daily calories. [If you still want to do it by hand, then you can add 20% to the number if you’re sedentary, 30% if you’re fairly active, 40% if you’re moderately active (almost daily exercise), 50% if you exercise daily or exercise for long intervals, or 60% for true athletes.]

Okay, now you’ve used the calculator and you see what your “maintenance” number of calories is, or basically, how many calories you could eat and stay the same weight (assuming you’re maintaining whatever activity level you’ve entered). So, lets say you want to lose one pound of fat a week. A pound of fat is equal to 3,500 calories, so if you divide that by seven for the number of days in a week, then you have to cut 500 calories out of your daily diet.

So, if I am a 6’2″, 29 yr old male who weighs 215 lbs and exercises 3 times a week, then my maintenance level of daily calories is 2,831. Now that I want to lose a pound a week, I should eat 2,331 calories per day to lose that weight.

This can feel a bit drastic to some, so remember you can also increase your activity level to try and meet in the middle, so go for a walk to help burn 250 calories and then you’ll have that much less to cut out of your diet. Also, make healthy food choices. Opt for grilled instead of fried foods. Watch the calories you are drinking – they add up faster than you think, i.e., sodas, juices, sports-drinks…

Beware Eating Too Few Calories

There may be the temptation to drastically reduce your calorie intake to lose weight fast. This is counterproductive, though, and can cause a few bad things to happen.

• Your body may begin to use it’s own muscle as food to fill in the nutritional gap – this is called catabolism.


• Instead of constantly increasing your metabolism, your body may lower your metabolic rate, as you are effectively putting your body in starvation mode. What’s more, with the muscle loss through catabolism you are reducing the number of calories your body would naturally burn. Muscle requires calories for maintenance.


• Lets now talk about what it’s like to be starving. You have little energy, are tired and fatigued, and you will most likely not be a very pleasant person to be around. Don’t underestimate the potential for grumpiness – I am a super laid-back person and almost every time I’ve ever blown my lid hunger was a contributing factor.

Fat Loss vs Muscle Building

Muscle needs calories for growth, so when you restrict your calories you can negatively affect muscle building. This is why I think it’s best – based on what I’ve read – to decrease calories gradually while increasing your exercise (both cardio and resistance/weight training). Building muscle while reducing fat is more beneficial than simply weighing less.

This combo approach to weight loss is the best path for a truly healthy body and best for achieving a healthier body composition. One pound of fat occupies a lot more volume than one pound of muscle. This is how you can have two 200lb 6ft tall guys, one with 50% body fat and another with 15% body fat wearing different sized clothing. Also, reduced abdominal belly-fat can reduce your chances of suffering from a variety of health problems. There is also evidence that a pound of muscle burns more calories than a pound of fat, though the number of calories is hard to pinpoint and has been cited as anywhere from 6 to 100 extra calories per day, but evidence shows its probably closer to the lower number.

Varying Daily Calories Eaten or ZigZagging

I recently read an interesting idea for breaking through weight-loss plateaus by varying daily caloric intake. There is an idea that our bodies adjust their metabolisms for whatever our regular daily intake is, and that to trick our bodies we shouldn’t consume the same number of calories per day, but should instead jump around an average number. So for instance if you are dropping down from 2500 calories per day to 2000, vary your daily intake from say 1800 to 2200 calories, averaging 2000 per day during the week. The idea is that this may help when you find that decreasing your caloric intake to a set number isn’t working. Do I know if it works? Not sure, I but I figure it’s worth a try. For me, my cravings and food quantities eaten vary daily, and I imagine this to be true for most people. However, for you hyper organized and disciplined people, maybe give it a shot.

Summary and Pointers for: How Many Calories Should I Eat To Lose Weight?

• There is no set number. To lose weight you basically need to find out what your current basal metabolic rate is and eat a few hundred calories less.


• It’s best to combine increased exercise with a moderate drop in caloric intake, say 250 calories, aka a snickers bar


• Write down what you eat to keep track. It’s a drag at first, but we humans are creatures of habit and soon you’ll be able to easily calculate where you’re at without a pen and paper (or iPhone) For me, I know my turkey sandwich is around 500 calories, my cereal and milk around 400 calories, my morning apples around 100 calories – easily calculable. Helps me stay on course, and helped me drop 20 lbs in 3 mos.


• Try varying your caloric intake daily around a set number which is a few hundred calories less than what your currently eating, based, of course, on your own weight loss goals.


• Don’t cut calories drastically! Gradual reduction is safest, and starving yourself is just as bad for your health as overeating.