Metabolism & Activity

Those who want to lose weight and are not avid in their exercise do not want to dip below the 1200 calorie per day mark. This is because even at rest a body can burn up to 1,000 calories or more for basic body processes such as the functioning of the heart, breathing, producing body heat, sweating, sending messages to the brain and producing thousands of chemicals in the body; this is called basal or resting metabolic rate (BMR or RMR) and generally represents 60% of a person’s energy needs.

When the body is restricted in calories, it becomes more efficient by slowing down metabolism (the rate your body burns energy from food). This is how our bodies can survive a famine or fast. It causes muscle loss, a slower metabolism and inadequate intake of nutrients for good health and top performance in physical activity. If too little is eaten, then a body can end up too hungry and then over indulge. It is so important to be mindful of your hunger…eat when you are hungry but make good choices.

Include a fruit or vegetable with every meal or snack and carbohydrates should be whole grain for the added fiber and nutrients.To start off you can determine your resting metabolic rate (RMR) by multiplying your current body weight or desired body weight by 10 (weight loss of 1-2 pounds per week at most is healthy). Then calculate how many calories you need for your general daily activity level: a sedentary (sitting, driving, sleeping, reading, typing) person should add 20% to RMR; a lightly active (light housework, grocery shopping, leisurely walking) person add 30% to RMR; a moderately active (heavy housework, gardening, brisk walking, dancing, very little sitting) person should add 40% to RMR and a very active (physical sports, labor intensive employment) person should add 50% to RMR.

Then add the calories needed for a specific exercise you will be doing for that day to your RMR. I have included a list of physical activity and the calories burned per hour per pound of body weight. For example a female that weighs 165 pounds at 5’9″, needs 1650 calories for RMR (body weight X 10) or if she wants to weigh 160 pounds (within desirable body weight range for height), then her RMR needs are 1600 (desired body weight X 10). Let’s say she is moderately active so add another 40% to her RMR: 1600 X .40 (40%) = 640 so 1600 + 640 = 2240.

This amount of calories is adequate for a day that does not include any purposeful exercise. Let’s say this person goes horseback riding 3 times per week for an hour each time. This would add an additional 2.8 calories needed per hour per pound of body weight. So 160 pounds X 2.8 = 448, which would be added to the 2240 for a total of 2,688 calories on the days that she went horse riding for an hour. This caloric intake will allow for a slow healthy weight loss as it is based on a desired weight that is 5 pounds less than she currently weighs. Slow and steady weight loss stays off whereas quick weight loss is regained fast. Weight loss is a whole other detailed topic, I just touched on it here.

Remember that muscle weighs more and exercise such as bicycling, running and weights all increase our muscle mass. A Dietitian can also assess your body measurements with anthropometrics where your total body muscle and fat are calculated. This is a much better assessment than weighing yourself on a scale. It is best to get nutrition advice from a Registered Dietitian who are always accredited through the Commission on Dietetic Registration (CDR).

Calories Burned During Exercise:

You can use this information to determine a reasonable estimate of the amount of calories you burn when exercising at a comfortable pace. If you are pushing yourself hard, add more calories.

Badminton 2.6
Bicycling, 10 mph 2.7
Dancing 2.0
Gardening 3.2
Golf, walking w/out cart 2.3
Horse grooming 3.5
House cleaning 1.6
Hiking, hills 3.6
Horseback riding 2.8
Ice skating 2.6
Jogging, 6 mph 4.2
Jumping rope 3.8
Racquetball 4.1
Scuba diving 3.8
Snow shoveling, light 2.9
Skiing, cross country 3.7
Skiing, downhill 2.6
Swimming 3.5
Soccer 3.7
Tennis, singles 2.9
Tennis, doubles 1.8
Volleyball 2.2
Walking, 3.5 mph 2.4
Waterskiing 3.0
Weight training 1.9



Chart adapted from Nancy Clark’s Sports Nutrition Guidebook.