Although it’s human nature to want speedy results, the best weight loss is medium-paced and steady. Even though it doesn’t sound ideal, the best rate of weight loss is 1-2 pounds per week for women and 2-3 pounds per week for men. This rate assures the body that it’s not being starved and it has a chance to adapt to its new size and shape. Anything more than this and you probably won’t be able to maintain your loss.
By the time a couple months pass by, you’ll have lost anywhere from 16-24 pounds. This might not always sound like that much, but the next time you’re at a gym (you do go to the gym, right?) pick up a 20 pound dumbell and imagine that amount of fat gone from your body. 
Losing weight in a healthy way means that no major food groups are eliminated from the diet. While some extreme diets may yield more than the above recommended rate of weight loss, most end up gaining it back because it’s not a lifestyle that’s desirable to maintain. For long term success, it’s better to change certain habits (sugar, lack of exercise, extreme portions sizes) that you can commit to over the long haul.
