According to Harvard Health Publishing, the minimum caloric intake per day is 1,200 calories for women and 1,800 calories for men. Starvation calories are an intake of fewer than 600 calories per day, however; any caloric intake below the recommended minimum doesn't provide the body with the fuel it needs to function properly. A starvation diet doesn't promote weight loss because your metabolism slows down in response to low caloric intake. Moreover, because hunger and serious side effects are associated with this type of eating plans, it's unsustainable and dangerous.
Consumption of under 1,200 calories per day for women and 1,800 calories per day for men can eventually lead to starvation mode symptoms.
Calories Needed Per Day
The foods you eat contain calories, which provide all the cells in your body with the fuel needed to perform their functions. When you eat, the digestive system breaks food down to release energy, which the body either uses immediately or stores for later use.
According to an April 2019 review in StatPearls, the daily caloric intake (DCI) needed to maintain weight is 2,000 in women and 2,500 in men. The DCI needed to lose one pound per week is 1,500 in women and 2,000 in men.
However, all calories aren't equal. When eating to maintain weight loss, it's important to consider the type as well as the number of calories. The BetterHealth Channel recommends choosing nutrient-dense foods like fruits, vegetables, whole grains and lean protein, all of which don't contain excessive numbers of calories. Limit your consumption of solid fats and sugar because they aren't good sources of essential nutrients.
Medically Supervised Low-Calorie Diets
Authors of the review said the diets involve a daily intake of 450 to 800 calories per day, along with vitamin and mineral supplementation to compensate for the calorie restriction. Because the calorie deficit is short-term, it isn't considered starvation. This weight-loss intervention should only be followed under the strict supervision of a medical professional.
Starvation Mode Symptoms
During long-term calorie restriction, the body doesn't have adequate energy and nutrients, so it goes into a state called metabolic damage or starvation mode. The University of California at Berkeley Department of Nutritional Sciences defines this state as the body's efforts to maintain energy and prevent the life-threatening event — starvation.
The StatPearls review reports that, in a starvation diet, the body tries to hang on to every calorie possible. Metabolism slows markedly, and production of the stress hormone cortisol increases, which leads to weight gain. Trying to live on starvation calories manifests in multiple symptoms. These include electrolyte imbalances that can cause heart rhythm disorders and weakened bones. Effects on the brain involve impaired concentration and cognition. As the starvation continues and malnutrition is extreme, the heart, kidneys and muscles lose mass.
The Mayo Clinic warns that, in malnutrition or anorexia, every organ in the body may suffer harm which may not be fully reversible, even if the person starts eating better. Death can happen suddenly, whether or not a severe underweight condition is present, due to abnormal heart rhythms or electrolyte imbalances.
Body Mass Index
Body Mass Index (BMI) is the weight of a person in kilograms divided by the square of the person's height in meters. Although BMI isn't a direct measure of body fat, it moderately correlates with it, according to the Centers for Disease Control and Prevention. The agency categorizes BMIs of 18.5 to 24.9 as normal and BMIs below 18.5 as underweight.
When the BMI gets too low, it poses a threat to life. The World Health Association cautions that BMIs of less than 17 indicate moderate and severe thinness in adults. BMIs of less than 16 are linked to a high risk of ill health, lethargy, poor performance and death.
Safe Weight Loss
Diets, especially low-calorie diets, are frequently ineffective because the restrictions produce feelings of deprivation and negativity, which lead to overeating and eating disorders. Instead, the University of Michigan's University Health Services advises adopting a nutritious eating plan that has long-term sustainability. This means centering the diet around plant-based foods: In every meal, cover half the plate with vegetables, a fourth with grains and the other fourth with protein.
Before starting a weight loss program, ask your doctor for help in setting intermediate goals. A modest amount of weight reduction can make a big difference in wellness. Remember that healthy weight management is a lifestyle, rather than a diet.
It's beneficial to emulate the behaviors of people who have been successful in losing weight. These include weighing yourself often, eating regular meals that include breakfast and not allowing small indiscretions to turn into major weight gains.
Government Meal Guidelines
- Grains come in two varieties: whole and refined. Examples of whole grains include oatmeal, brown rice, bulgur wheat, barley and whole wheat. Refined grains refer to products made with white flour or white rice. At least half of your daily grains should be whole. A serving size is one slice of whole grain bread or 1/2 cup of cooked rice or cereal.
- Any fruit counts. A serving size is: 1 cup of fresh, frozen or canned fruit; 1 cup of 100 percent fruit juice; or 1/2 cup dried fruit.
- Vegetables come in five categories: starchy vegetables, dark green vegetables, legumes, red and orange vegetables and other vegetables. A serving size is 1 cup of raw or cooked vegetables, 1 cup vegetable juice or 2 cups leafy greens.
- Protein foods include beans, peas, seeds, nuts, eggs, soy products, poultry, seafood and red meat. Poultry and red meat choices should be lean or low-fat. A serving is: 1/2 cup cooked beans; 1/2 cup nuts and seeds; 1 tablespoon peanut butter; 1 egg; or 1 ounce of meat, poultry or fish.
- Dairy foods include milk, soy milk, yogurt and natural cheese. Although butter and cream cheese are dairy products, the USDA doesn't include them in this group. A serving size is: 1 cup of milk, 1 cup of yogurt or 1 1/2 ounces natural cheese.
- StatPearls: "Calories"
- Mayo Clinic: "Anorexia Nervosa"
- Centers for Disease Control and Prevention: "About Adult BMI"
- World Health Organization: "Nutrition Landscape Information System Interpretation Guide"
- University of Michigan: "Weight Reduction"
- United States Department of Agriculture: "Choose My Plate"
- Harvard Health Publishing: "Calorie Counting Made Easy"
- BetterHealth Channel: "Weight Loss - A Healthy Approach"
- Centers for Disease Control and Prevention: "Losing Weight"
- National Center for Biotechnology Information: "Obesity: Identification, Assessment and Management of Overweight and Obesity in Children, Young People and Adults: Partial Update of CG43"