Click here to go back to Articles



Understanding what exactly calories are and how they work can help you learn the best way to manage your intake and maintain a healthy weight.

Calories get a bad rap. We blame them for everything - from making us feel guilty about enjoying a hot fudge sundae with extra nuts to the way our jeans fit.

Yet, demonizing calories is like bad-mouthing oxygen: It's impossible to survive very long without either one. Calories fuel the body. We need them to survive.   So the best way to manage weight is to understand that body weight comes down to a simple equation of calories in (from food) versus calories out (as physical activity).

What exactly is a calorie?   In essence, it is a measurement of a unit of energy.   The number of calories in the foods you eat is a measure of the number of energy units that food supplies.   Those energy units are used by the body to fuel physical activity as well as all metabolic processes, from maintaining your heartbeat and growing hair to healing a scraped knee and building muscle.

Only four components of food supply calories: protein and carbohydrates (4 calories per gram), alcohol (7 calories per gram) and fat (9 calories per gram). Vitamins, minerals, phytochemicals, fiber and water do not supply calories.

It is important to ensure that you are taking in enough calories to balance the energy you exert.   However, a recent study showed that caloric restriction, even in non-obese people, translates into less oxidative damage in muscle cells.    As oxidative damage has been linked to aging, this could explain how limiting calorie intake without malnutrition extends life span.

So how do you figure out how many calories you need to cut to lose weight vs. how many calories you need to maintain weight?   First, you need to know how many calories you're currently consuming. You can figure that out by keeping a food journal: tracking calories for everything you eat during a period including at least two weekdays and one weekend day (since people tend to eat differently on weekends). Figure out the calorie count for each food item, then tally the total calories and divide by the number of days you tracked your intake to find your daily average.

Or you can roughly estimate your caloric intake by using this formula: If you are age 30 or under, multiply your weight by 6.7 and add 487; women who are 31-60 should multiply their weight by 4 and add 829. Then, multiply the total by 1.3 if you're sedentary (don't work out at all), 1.5 if you're slightly active (work out three to four times a week for one hour), 1.6 if you're moderately active (work out four to five times a week for one hour) or 1.9 if you're very active (work out almost every day for one hour).

Once you know about how many calories you consume per day, try this 100/100 plan: To lose a couple of pounds a month, cut 100 calories from your daily diet and add 100 calories in exercise. This is as easy as eliminating the pat of butter on a slice of toast and walking 20 minutes every day.

The bottom line is that the more you understand about how calories work and how much are contained in the food you can consume, the better able you will be to eat the healthy amount and kind necessary for you to maximize your energy and maintain the right weight.

For even more info on calories, check out this article