Asked by Andy Wolfe, New Jersey
Hi, I'm looking to lose 15-20 pounds in the next month to six weeks. Is it really possible to do so just by exercising (dumbbell curls, running on the treadmill) for about two hours every other day along with staying away from fatty foods?
Diet and Fitness Expert
Dr. Melina Jampolis
Physician Nutrition Specialist
Hi Andy -- Without knowing more about you (age, height, weight, medical history), it's impossible to answer this question accurately, but I would like to make a few comments as your question brings up some important points. First of all, we need to review a little math. To lose 1 pound of fat (not muscle or water), you need a 3,500 calorie deficit. That would mean to lose 3 pounds of fat per week (for a total of 18 pounds in six weeks), you would need a 10,500 calorie weekly deficit or a 1,500 calorie daily deficit.
I went to one of my favorite Web sites, caloriesperhour.com, and made a few assumptions to give you even more information to work with. On average, a 5-foot-10, 195-pound, moderately active 40-year-old man needs about 2,792 calories per day to maintain his current weight. The same man would burn approximately 1,238 calories running at a moderate pace (6.7 miles per hour) for one hour and lifting weights moderately for one hour. Assuming that you performed that workout three days per week, you would need to cut calories by about 750 calories on the days that you exercise (that would mean eating 2,792-750 = 2,042 calories) and by 1,100 calories on the days that you don't (that would mean eating 2,792-1,100 = 1,692 calories) to lose 3 pounds of fat per week. This would be a fairly aggressive caloric reduction and might lead to loss of muscle mass, which is not a good idea for long-term health and weight maintenance.
Staying away from fatty foods is one way to cut calories, since fat has more than double the calories per gram of both carbohydrates and protein, but you need some fat in your diet for optimal health (at least 20 percent), especially healthy fats including nuts and seeds, avocado, and olive or canola oil. Depending on how much fat you are currently consuming, cutting back somewhat may help, but I would also recommend cutting back on sugar and sugary beverages, refined carbohydrates and processed foods and significantly increasing your fruit and vegetable intake.
So depending on your starting point, you may be able to reach your goal, but it is going to be challenging. I would prefer to see you aim for about 2 pounds of fat loss per week for a total of 12 pounds in 6 weeks. You didn't gain the extra 15-20 pounds that quickly (I assume), so why rush to lose it too quickly and possibly gain it back and more!
Can eating too much fruit keep me from losing weight?
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