Nutrisystem is a weight loss company that offers a subscription-based diet plan. The plan provides customers with pre-packaged meals and snacks that are low in calories and nutritionally balanced. Customers can also receive support from counselors and dietitians by phone or online chat. Nutrisystem is a weight loss company that offers a subscription-based diet plan. The plan provides customers with pre-packaged meals and snacks that are low in calories and nutritionally balanced. Customers can also receive support from counselors and dietitians by phone or online chat.