Calorie restriction diet is intended to promote weight loss and improved well-being by drastically reducing daily calorie intake. These diets often involve the use of meal replacement items, including meal-replacement shakes, soups, and bars.
Many calorie-restricted diets reduce daily calorie intake to 1,200 calories a day, and some plans reduce this intake to no more than eight hundred calories each day.
Calorie restriction diets may be recommended by doctors in cases where patients have a body mass index of thirty or above, and they might also be considered for patients with body mass indices of twenty-seven or higher who also have conditions such as diabetes or hypertension.
Since calorie restriction involves some level of risk, especially when they drop below 1200 calories, patients should ensure they are monitored by a doctor while following the diet.
Calorie Restriction Diet Plans Explained
The guide below explains some of the most popular types of calorie restriction diets, and it also includes information about potential benefits, side effects, and alternatives.
Defining Calorie Restriction
In terms of defining calorie restriction, most experts agree it consists of a thirty to forty percent reduction in daily caloric intake.
Individual calorie needs vary depending on an individual’s gender, age, and weight, so a thirty to forty percent reduction generally means consuming between eight hundred and 1,500 calories each day.
Some calorie restriction plans include a daily calorie intake of approximately four hundred to seven hundred calories. Also known as very-low-calorie diets, these forms of calorie restriction are typically followed for one to three months, and patients must be monitored by a physician.
Alternatively, newer forms of calorie restriction may focus on restricting weekly calorie intake. These forms of restriction have a daily limit of five to seven hundred calories for two or three days of the week and patients can eat more calories on the other days of the week. For some patients, these plans are easier to maintain.
Examples of Calorie Restriction Diets
The Cambridge diet is one of the primary examples of calorie restriction diets. Developed in Britain in the 1980s, the diet begins with a four-week period designed to promote weight loss of at least three to five pounds per week.
Patients consume 415 to 554 calories per day, and the calories come exclusively from specialized meal replacement shakes and soups. Women are allowed three meal replacement products per day, and men are to consume four.
No additional food is permitted, and patients are encouraged to drink at least two quarts of water per day. After the initial four-week period, the plan enters a stabilization phase that allows up to 790 calories per day.
Patients in this phase can have three meal replacement products and one meal of green vegetables, cottage cheese, and three ounces of fish or poultry. A similar calorie restriction program is run by doctors at UCLA Health.
Known as the RFO Weight Management Program, this program also uses meal replacement shakes and soups and allows for a range of four hundred to one thousand calories per day.
Patients on the program have their weight, blood pressure, potassium, and cardiac health monitored several times a month.
Patients who do not want to use meal replacement products often create their own version of a calorie-restricted diet by restricting their eating to calorie-controlled amounts of certain food groups. The grapefruit diet and the cabbage soup diet are examples of these diets.
Claimed Health Benefits
The claimed health benefits of calorie restriction diets extend far beyond weight loss. Proponents of these approaches assert these diets can improve cardiovascular health and even extend lifespan.
Although more research is needed, studies in animals suggest engaging in calorie restriction extends lifespan by as much as fifty percent. Research conducted in primates also suggests restriction could reduce a dieter’s risk of cancer and age-related memory issues.
Studies in humans have shown calorie restriction improves markers of cardiovascular health, providing reductions in cholesterol, blood pressure, waist circumference, and blood sugar.
A study of diabetes patients published in 2017 found caloric restriction was effective in reducing blood sugar and blood pressure for this patient population, and the subjects also had reductions in inflammatory markers.
Additional research has shown calorie restriction can reduce oxidative stress, and patients who follow this dietary approach for several months have also reported increased mood and reduced feelings of stress and tension.
Risks of Calorie Restriction
Patients who practice calorie restriction diets may wish to do so under medical supervision, and calorie restriction is not usually recommended for individuals over fifty years old or for those who have chronic health conditions that require medication.
Some of the potential risks of calorie restriction include heart rhythm abnormalities, nutrient deficiencies, liver or kidney damage, and weakening of the bones.
Studies of patients who were heavily involved in sports such as gymnastics or taekwondo while following calorie restriction plans concluded that such patients had decreased immune system function and an increased risk of infection.
The rapid weight loss that often results from calorie restriction could elevate an individual’s risk of developing gallstones. Patients who experience pain in the upper right part of the abdomen while on a calorie restriction program should see a doctor as soon as possible.
Alternatives to Calorie Restriction
Several alternatives to calorie restriction are available, and these tend to focus on the quality of food and certain food groups. The ketogenic, paleo, vegan, vegetarian, and Whole30 diets are some examples of these approaches.
While some patients using these methods choose to count calories, others simply focus on getting a sufficient quantity of particular nutrients.
For example, patients might count their intake of carbohydrates, protein, fat, or sugar. Many alternatives to calorie restriction emphasize the use of whole foods such as raw fruits and vegetables, and eating organic food is encouraged.
Another alternative approach known as intuitive eating helps individuals learn to distinguish physical hunger from emotional hunger.
Followers of this plan listen to their body cues, and they learn to eat only when they are physically hungry. No calorie counting is required, and the plan does not place any limits on the type of food an individual can eat.