According to WebMD, the best way to lose weight fast is to maintain a diet and exercise regimen that produces a 500-calorie deficit every day. A calorie deficit is the difference between the number of calories burned and the number of calories consumed. For the average dieter, a daily 500 calorie deficit produces a loss of 1 to 2 pounds per week.
To aid in calorie counting, WebMD suggests keeping a food and exercise diary or journal to keep track of calorie intake and output. For intake, the site recommends avoiding fatty meat and dairy, added sugars, salt and starch in favor of fruits, vegetables, lean meats, low-fat dairy and fish. Tips from the Mayo Clinic include either avoiding high-calorie foods or replacing them with low-calorie substitutes. The Mayo Clinic also suggests reducing portion sizes. Health Magazine and the Mayo Clinic agree that dieters need to purge pantries of unhealthy food and avoid junk food aisles at the grocery store.
For the exercise portion of the plan, WebMD suggests dieters engage in at least one hour of exercise every day, and the Mayo Clinic also supports increasing physical exercise. Health Magazine endorses short bouts of exercise throughout the day, such as crunches and squats.