Julie Chrisley and Dorinda Medley Join Marie Osmond in Inspiring New Nutrisystem "Real Talk" Commercial. Nutrisystem, Inc.

about 1,000 calories per day The Fast 5 week meal plan provides about 1,000 calories per day. After those initial 7 days, the meal plans in the included Meal Guide or on the NuMi App will switch to either a 1,200 calorie meal plan for women or a 1,500 calorie meal plan for men.

The Fast 5 week is included with select Nutrisystem plans, including Uniquely Yours Max+.

Bring a water bottle with you and sip it steadily throughout the day. If you need a change from plain water, you can also enjoy zero-calorie seltzer and sparkling water, black coffee, unsweetened tea and lemon water to help you reach that daily goal. Avoid alcohol until you get into your second week.

Harold J. Katz 1972-today: Nutrisystem Founded by Harold J. Katz, then 34, who was inspired by his mother's continuing struggle to lose weight, Nutrisystem became one of the earliest meal delivery providers in the diet industry.

The Nutrisystem diet allows lean protein, healthy fats, low-fat dairy products, nonstarchy vegetables, certain fruits and whole-wheat carbohydrates. The program doesn't encourage sugary desserts, high-calorie meals, deep-fried foods, butter, starchy vegetables, such as potatoes, and sugary drinks.

Fasting did seem to spur noticeable short-term weight loss, the researchers found. People who fasted for five days lost about 4% to 6% of their weight; those who fasted for seven to 10 days lost about 2% to 10%, and those who fasted for 15 to 20 days lost 7% to 10%.

The 5:2: Eat no more than 500 cals a day, twice a week. Simple and flexible, you choose your own fast days. But 500 cals can feel restrictive and difficult to stick to. Fast 800: Michael Mosley's updated version of 5:2 advocating two days on 800 calories, and five on a lower carbohydrate regime.

7-Day Nutrisystem® Fast Five 7-Day Diet Kit, Helps Support Weight Loss, 28 Delicious Meals & Snacks Plus Chocolate Protein ProSync Shakes.

If you're trying to decide between WW and Nutrisystem, consider which one better suits your needs and preferences. Although Nutrisystem is a bit more expensive, it may be a better option for those looking to lose weight in the short term and save time on cooking and meal prep.

Just be sure to watch out for added sugars, and opt for unsweetened versions. Best choices: A one-cup serving of fat-free milk is a PowerFuel, because it is loaded with protein. A cup of unsweetened soy, almond or coconut milk also qualifies as a PowerFuel that fits into your Nutrisystem weight loss plan.

The Nutrisystem website states that you can expect to lose 1–2 pounds (0.5–1 kg) per week if you follow the diet, and that men can lose up to 18 pounds (2.25 kg) the first month (1).