How Many Calories Should I Eat a Day

How may calories to I need to eat per day? This is a question that’s bothering a lot of people. It seems that the more we get swamped by weight loss and dieting information, the harder it gets to find answers to the most basic of questions. After all, weight loss is about calories. At the end of the day it’s all a matter of how much you put in and how much you burn off.

However, estimating how many calories you should eat a day is not easy and hardly ever accurate. Your metabolic rate depends on a lot of factors: age, weight, height, ethnicity, genetics, and so on. In addition, the very food you eat can change your metabolism.

One way to tackle this question is start with your BMR, your Basal Metabolic Rate. This is the amount of calories which your body burns each day to carry out the most basic functions and necessity. This does not include working out.

There are various formulas which give estimates of BMR (also known as Resting Metabolic Rate (RMR) and Resting Energy Expenditure (REE)). None of them is wholly accurate but they can provide you with a rough estimate by which to plan your eating routine.

In a study published in 2005 by the ADA (American Dietetic Association) which examined the accuracy of various methods to calculate BMR, the Mifflin-St Jeor equation was found the most likely to give an accurate estimation of BMR. However, even this equation was found to do so within a 10% error margin and has various further limitations that may make it even less accurate than that.

The Mifflin-St Jeor equation is as follows:

MEN: cal/day = 5 + 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years)

WOMEN: cal/day = 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years) – 161

Again, this was found to be the most accurate formula with limitations.

Two of the other equations examined in the study were the Harris-Benedict and the Owen equations.

The Harris-Benedict equation is as follows:

MEN: cal/day = 66 + 13.75 x weight(kg)+5 x height (cm) -6.76 x age(years)
WOMEN: cal/day = 655 + 9.56 x weight (kg) + 1.85 x height (cm) -4.68 x age (years)

The Owen equation is as follows:

MEN: cal/day = 879 + 10.2 x weight (kg)
WOMEN: cal/day = 795 + 7.2  x weight (kg)

As you can see, the Owen equation doesn’t even account for age, making it wildly inaccurate.

Basal Metabolic Rate Limitations

In addition to the inherent inaccuracies of either of these equations and any other that may exist, the BMR calculation has one basic flaw: it does not account for physical activity, whether it’s working out or your own lifestyle. Some people lead a more sedentary lifestyle because they have an office job while others do a more physical type of work. It’s only logical that the latter would need to eat more calories per day just to maintain their weight.

The American Heart Association published a simple table on the daily calorie needs of men and women at various ages depending on their activity level. It also shows how older people require less calories to meet their basic daily needs. However, the big difference is in how your activity level changes the amount of calories you can eat just to maintain your weight.

For instance women 31 – 50 years old who lead a sedentary life need just 1,800 calories per day. Those who lead a very active lifestyle (the equivalent of walking 3 miles a day at 3 miles per hour or more) need 2,200 calories to maintain their weight.

Men at the 31 – 50 age group also have a big difference between those who are active and those who are not. Men leading sedentary lifestyles can do with just 2,200 calories each day. Those who are very active can eat 2,800 – 3000 calories each day.

For women 19 – 30 the calorie range is 2,000 to 2,400 and for men of similar age it’s 2,400 to 3,000. Naturally, the more active you are the higher this number becomes, the lower your activity level is the less calories you will need to eat.

Should you worry about calories at all?

As you can see it’s pretty tough to know how many calories you really need to eat a day. In fact, it seems quite an impossibility to pinpoint down the exact number. Either you’re happy with estimates or you’re not.

But do calories even matter? Should you worry about them at all?

The answer, in my opinion, is yes and no. Yes because you should be aware of how many calories you’re eating in broad terms. There’s no escaping it, your weight gain or loss depends on it. No because placing to much emphasis on calories and starting to count them carefully can be detrimental to your long term fat loss goals.

Remember, losing weight is more about how many calories you eat. As it’s hard to know for sure how many calories you need, the easier thing to do is to focus on ways to boost your metabolism and ensuring that your body acts like a fat burning furnace, melting away calories and fat as fast as it can. This is done with correct eating and a regular fitness routine.

Two excellent programs that can help you in that respect are Burn the Fat Feed the Muscle and the popular Truth About Abs program. I feel that either of these plans can help you burn fat and lose weight without having to count calories or rely on inaccurate formulas.