A 10 to 15 pound weight loss can have a significant impact on your health -- if you're overweight, it might mean enough weight loss to help improve markers of health, including blood pressure and cholesterol levels. How long it takes to lose this weight depends a lot on your current size and your dedication to achieving the loss. The Centers for Disease Control and Prevention, as well as other health institutions, recommends losing weight at a gradual rate of 1 to 2 pounds per week. At this rate, you'll reach your goal of 10 to 15 pounds lost in as soon as five weeks or as long as 15 weeks.
How Weight Loss Works
Eating fewer calories than you burn a day leads to an energy deficit and subsequent weight loss. Make that deficit equal to 3,500 calories, and you'll lose one pound. A deficit of 500 to 1,000 calories daily adds up to a loss of 1 to 2 pounds per week.
You create a deficit by eating less and moving more. For example, you can trim your diet by just 250 calories and add 250 calories of additional exercise daily to create the 500-calorie-per-day loss required to lose a pound per week. Trim calories from your diet by staying away from refined grains, sugar and saturated fat. Make your meals consist primarily of lean protein, vegetables and whole grains. Choose plain yogurt, scant handfuls of raw nuts, low-fat cheese and fresh fruit for snacks.
Gradual Weight Loss Is Best
Experts recommend a 1- to 2-pound loss rate because most people find it feasible. Losing weight too quickly can lead to serious side effects, such as gallstones. It's also hard for most people to successfully maintain a weight loss rate of more than 2 pounds per week for any length of time. The dietary restrictions and exercise requirements are just too great.
A crash or fad diet might help you lose weight faster, but, when weight is lost so quickly, it usually returns just as fast. Methods of fast weight loss often ban entire categories of nutrients, or food altogether in the case of fasts. Severe deprivation also slows your metabolism so it's harder to lose the next time you try. Fast weight loss also happens because you lose a lot of water and lean tissue, not fat. A gradual approach that takes more than two months to lose the 10 to 15 pounds is more likely to encourage fat loss.
Larger People Lose 10 to 15 Pounds Faster
If you have a lot of weight to lose, losing 10 to 15 pounds may happen relatively quickly -- even within a week or two of dedicated low-calorie dieting and mild increases in movement. If you are just 10 to 15 pounds away from your ideal weight, losing it will take considerably longer, however. When your body is larger, it takes more calories to maintain your weight. You can cut calories drastically and still get all the nutrients you need. Extremely overweight people also lose a high volume of water weight in the first few weeks of a weight-loss plan, simply because they carry more excess fluid.
Take Steps to Make Weight Loss Sustainable
The closer you are to your ideal weight, the fewer calories you need to consume for weight maintenance, so you'll need even fewer for weight loss. It's harder to create a dramatic calorie deficit so weight loss occurs more slowly. Set your goal for a 1/2-pound weight loss per week, and you only need to create a deficit of 250 calories per day.
For some people, such as the average sedentary woman over the age of 50, creating the 500- to 1,000-calorie deficit is impossible without restricting intake to fewer than 1,200 calories per day. Consuming fewer than 1,200 calories isn't recommended as it's difficult to follow, slows your metabolism and can leave you missing certain nutrients.
Slower weight loss also means you don't have to make drastic, unsustainable changes. It might take you 20 to 30 weeks to lose 10 to 15 pounds, but you're more likely to find the process manageable and be able to keep the weight off for the long run.