Two recent studies by diet and health researchers confirm that dieting alone is not the best or the healthiest way to go about weight loss.
Dennis T. Villareal, MD, Washington University School of Medicine, St. Louis. Louis, and colleagues studied the effects of weight loss on bone loss in 48 adults with an average age of 57. Nineteen was assigned to follow a calorie-restricted diet, 19 to eat the same number of calories and begin an exercise, and 10 to receive information on healthy lifestyles only when requested.
All participants were weighed at the beginning of the study and again after one, three, six, nine and 12 months. Bone mineral density was measured every three months.
After one year, those in the calorie restriction group lost an average of 18.1 pounds, those in the exercise intervention group lost 14.8 pounds and those in the healthy lifestyle group maintained their weight. Individuals in the calorie-restriction group also lost an average of 2.2 percent of their bone density in the lower spine, 2.2 percent at the hip and 2.1 percent at the top end of the femur – all high-risk fracture sites.
There were no significant changes in bone mineral density in the exercise or healthy lifestyle groups.
Muscles pulling on bones during exercise is thought to produce strains in the skeleton that stimulate new bone production. "Our results are consistent with an osteoprotective effect of exercise-induced mechanical strain on the skeleton and consequent increase in bone turnover," the authors continue.
In another study, a Washington University team of scientists studied healthy 50 to 60-year olds body mass index was between 23 and 30, placing them at the high end of normal weight or overweight. Of the 34 study participants, 18 dieted and 16 exercised to lose weight.
After one year the participants lost an average of between 9 and 10 percent of their total body weight.
Those who died lost muscle mass while those who exercised did not. This is because the exercisers routiniously challenged their muscles, which preceded muscle tissue from degrading. A subgroup that did 30 minutes per day of extra exercise lost an average of 18 percent of their total body weight with no loss of muscle tissue.
The lesson is clear. If you diet alone to lose weight you are only creating a lighter bag of skin. For healthy weight loss you must work your muscles and pound your bones.
Here is a simple formula that you can use to lose two pounds of body fat per week. One pound of fat = 3,500 calories. If you do nothing to change your eating habits, and exercise to burn 7,000 calories per week, you will lose two pounds of body fat per week and keep or build your bone density and muscle at the same time. A win-win.
Putting your feet on the ground at about 75 counts per minute burns .078 Calories / Minute / Pound of Body Weight, or more easily remembered, 7.8 calories per minute, or 468 calories per hour, per 100 pounds of body weight.
A 200 pound person would require about 7 1/2 hours per week of exercise that pounded their feet on the ground 75 times per minute. Use this formula to convert for your situation:
(Your Body Weight / 100) * 468 * (Steps Per Minute / 75) = Calories Per Hour. Divide 7,000 by the Calories Per Hour figure and that is how many hours of exercise per week you must do to lose 2 pounds of body fat. If you can not find a way to lose 2 pounds of body fat per week then shoot to eliminate 1 pound of body fat per week. That is still 52 pounds of healthy weight loss per year.