The key to achieving lasting weight loss is to follow the established safe guideline of 1 to 2 pounds per week, according to the Centers for Disease Control and Prevention. Crash diets are unhealthy, and the weight you lose is likely to come back when you resume a normal diet. To lose 25 pounds in three months, you’ll need to significantly reduce calories; however, with some smart dietary changes and increased exercise, you can make your goal while maintaining good health.
Determine how many calories you need each day to maintain your weight. There are complicated formulas that calculate this target for you, or you can use the established averages for your gender and age published by groups like the American Heart Association. For example, a moderately active 25-year-old male burns 2,600 to 2,800 calories per day.
Calculate the calorie deficit required to meet your goal. One pound equals 3,500 calories, according to the American Academy of Family Physicians. To lose 2 pounds per week and reach your goal of 25 pounds in three months, you’ll need to cut 7,000 calories per week, or 1,000 per day. Don't eat fewer than 1,200 calories per day if you're female, or 1,500 calories per day if you're male, even if it means losing weight more slowly than you'd like.
Build a meal plan that meets your calorie target, and place the emphasis on nutrient-dense foods like fruits and vegetables. It’s very difficult to get the recommended minimum of vitamins and minerals on a severely reduced calorie diet. Nutrient-dense foods are those that pack lots of micronutrients into foods that are low in calories. Use the U.S. Department of Agriculture's MyPlate to guide your food group choices.
Cut the empty calories first. When you evaluate what you eat each day at your current weight, you’re likely to find big savings just by reducing the unnecessary items. For example, you can cut your daily calorie intake by up to 350 calories just by skipping the once-daily soda and the mocha java special from your local coffee shop.
Eat three meals per day, and budget one to two snacks into your calorie target. Cutting calories should never mean skipping meals. Food is fuel, and your body needs consistent input to keep your metabolism humming. The steady intake will help you deal with unexpected cravings.
Measure your portions. Once you’ve established your calorie target, accurate accounting is a must. “Eyeballing” what you think is a portion is a recipe for disaster.
Write down everything you eat. If you have a written meal plan, check off each item as you eat it, and write in any slips and the number of calories they contain. A bad day does not mean all is lost. You can make up the excess calories from one bad day slowly over the rest of the week through exercise and additional calorie cutting.
Perform moderate-to-vigorous cardio exercises such as jogging and swimming 30 to 60 minutes per day. Use an online calorie calculator to estimate the calorie burn you get for various activities. Remember, not all exercise happens at the gym. Physically demanding weekend chores, like yard work, are significant calorie burners.
Train your muscles twice weekly by lifting weights or doing pushups, V-ups, squats and chinups. These activities build muscle tissue, which helps increase your metabolism.
Vary your workouts to help prevent boredom and prevent overuse injury. For example, use a stationary bike one day, then take a brisk walk up hilly terrain the next.