Eating 1000 calories per day can be an effective way to lose weight, as it creates a calorie deficit in the body. When the body consumes fewer calories than it needs, it starts to burn stored fat for energy, leading to weight loss.However, it's important to note that weight loss is not guaranteed with a 1000-calorie diet plan. The amount of weight a person can lose depends on various factors such as age, sex, height, weight, and activity level. Also, weight loss is not always linear, and it may vary from week to week. You can read about them on Outlook Health.