Low-Calorie Diets: Characteristics, Effects, and Examples

Low-calorie diets are capable of promoting weight loss when they are well designed and controlled by a professional. Learn more.

Written and verified by el nutricionista Saúl Sánchez.

Last update: 25 March, 2023

Low-calorie diets are designed to promote weight loss. They’ve spread throughout the world and can be effective, as long as they’re prescribed correctly. The problem is that many of these plans are too restrictive.

It’s advisable to go to a professional before starting a regimen of this type in order to ensure that it’s not counterproductive. It must be taken into account that there are situations in which hypocaloric diets shouldn’t be proposed, as is the case with pregnant women.

The characteristics of hypocaloric diets

If all hypocaloric diets have something in common, it’s that they seek to generate weight loss by reducing the calories ingested. This method has proven to be effective. If the energy balance is unbalanced in favor of caloric expenditure, progressive oxidation of adipose tissue occurs.

Most of these eating guidelines are based on the restriction of the most energetic foods. These are usually those with the highest fat content, soft drinks, and alcoholic beverages. In addition, the consumption of fresh foods is prioritized over ultra-processed ones, as the latter usually contain more calories.

Modern low-calorie diets

Despite the fact that the classical method consists of restricting the consumption of certain foods, hypocaloric diets have currently been designed from a different point of view. The concept of intermittent fasting has been introduced, and its health benefits have been demonstrated.

In this way, it’s possible to reduce the number of intakes that take place during the day. A fasting period of at least 16 hours is suggested, with varied dishes during the time in which food consumption is allowed.

People who employ this mechanism enjoy better adaptation because it causes less anxiety and appetite. However, it’s not exempt from limitations, as in the case of children or pregnant women, it’s not advisable.

The effects of hypocaloric diets

According to what has been mentioned, the most notable effect of hypocaloric diets is the progressive reduction of body weight. This generates an improvement in the functioning of the body, as being overweight is associated with a greater risk of getting sick. This is evidenced by a study published in the journal Circulation Research.

At the same time, current research has managed to show that this type of hypocaloric diet can cause an increase in life expectancy. This condition derives from less inflammation and oxidation at a systemic level, which causes less wear and tear on organs and tissues.

In addition, the caloric restriction caused is capable of generating autophagy. Through this mechanism, inefficient cells are destroyed and the replication of those that perform their function correctly is stimulated.

The limitations of hypocaloric diets

Like many other dietary approaches, hypocaloric feeding has a series of limitations. In the first place, it defends that weight loss originates only from a mathematical perspective. In reality, there are other factors that have a decisive influence.

The most current dietary plans are committed to the integration of healthy lifestyle habits. The aim is thus to improve the functioning of the hormonal system, which can have an impact on the oxidation of lipids.

We mustn’t forget either that certain concepts, such as metabolic flexibility, are closely related to the body’s efficiency in using lipids as the main energy source. This mechanism depends on the cells’ sensitivity to insulin, according to a study published in Cell Metabolism.

When are hypocaloric diets not recommended?

There are certain situations in which it’s not advisable to consider a hypocaloric diet. One of them is pregnancy. During this period, the body must receive a higher supply of nutrients.

Restricting intake can condition the development of the fetus, generating malformations. In fact, during pregnancy, the consumption of nutritional supplements tends to be recommended in order to prevent deficits. An example is that of folic acid, which has been shown to be able to reduce the incidence of developing spina bifida.

Another case in which it’s not a good idea to start low-calorie diets is during adolescence. This is a growth stage, and meeting nutritional requirements is essential. Of course, this doesn’t mean that teens have to eat excessively, as being overweight could condition the functioning of the body.

Finally, care must be taken with hypocaloric diets in the context of elite sports. Athletes are often forced to reduce their weight in order to compete. However, approaching an energy deficit that’s too aggressive can have an impact on performance, affecting subsequent competition.

It’s crucial to put yourself in the hands of a professional in this kind of situation so that both performance and health aren’t affected. It should be noted that an inefficient intake of nutrients can also increase the risk of injury.

Examples of low-calorie diets

We’re going to offer you an example of a conventional hypocaloric diet and another more current model so that you get an idea of how these menus are prepared.

Traditional low-calorie diet

• Breakfast: 8 ounces of milk with 1 cup of oats, blueberries, and 1/8 cup of nuts.
• Mid-morning: 1 portion of fruit.
• Noon: 2 baked chicken thighs with broccoli and 3 ounces of sweet potato. Plain yogurt.
• Snack: 2 corn pancakes with light spreadable cheese and nuts.
• Dinner: 1 slice of grilled cod with mixed salad.

Updated low-calorie diet

• Breakfast: Intermittent fasting until 2:00 p.m. Coffee or tea without sugar or milk is allowed during the fasting period.
• Noon: 5 ounces of grilled salmon with 3 grams of boiled potato and cauliflower. Plain yogurt.
• Snack: 2 unsweetened natural yogurts with 1/8 cup of walnuts and raspberries.
• Dinner: 2 ounces of grilled beef with sautéed vegetables.

As you can see, both approaches are committed to oil-free cooking methods, as well as a slight reduction in carbohydrates. Fresh foods are the protagonists, minimizing the consumption of ultra-processed foods. At the same time, dairy consumption is promoted and is intended to ensure adequate protein intake.

Supplements in hypocaloric diets

Supplements are often prescribed in the context of low-calorie diets. This is done in order to guarantee an adequate protein intake or to prevent the deficit of certain nutrients that can be considered key.

The most common in this regard is to introduce an omega-3 supplement or antioxidants to keep inflammation under control and prevent the development of complex diseases. The inclusion of a product with a high vitamin C or D content can also be considered.

Finally, it should be noted that it’s also possible to add melatonin. This neurohormone will help to improve the quality of sleep, stabilizing circadian rhythms.

Low-calorie diets are a safe-passage toward weight loss

As you’ve seen, low-calorie diets are effective in promoting weight loss and achieving optimal body composition. However, they must be combined with more current strategies.

Keep in mind that an excessively restrictive or poorly planned hypocaloric diet can be counterproductive. It’s possible to generate a nutritional deficiency that ends in the development of a disease. It can also alter metabolism, leading to a rebound effect afterward.

In this regard, it’s best to visit a nutrition professional to get an individualized plan adapted to the needs of each person. In this way, the option of supplementation can also be evaluated, with all the benefits that it can bring when it’s considered appropriately.