How to lose weight in 7 days. Going on a diet, we want to see the result as soon as possible. As luck would have it, weight loss occurs gradually, and one run will not lead to instant results. The more carefully you plan your menu for the day (or even a week in advance), the less likely you are to roll into fast food closest. Try to take Sunday for the purchase of products for the week ahead and cooking healthy dishes. Some of them can be frozen, divided into portions and laid out in boxes.