Fast Diet: Advantages, Disadvantages, Types and Risks

Diets represent a resource, along with the practice of sports, when we want to improve health and physical appearance.

However, we require some quick results in the physical aspect on essential occasions, so we look for an emergency regimen to lose weight and opt for the so-called “fast diets.”

Fast diets have disadvantages and advantages that must be assessed when choosing the method to lose weight.

Most diets decrease weight and volume but not fat because they concentrate on suppressing excess accumulated liquids.

A fast diet should not be maintained for long since it is usually rigorous and involves considerable nutrient restrictions.

Advantages and disadvantages of the Fast Diet

All these diets to lose weight quickly have their advantages and disadvantages that must be known before starting a diet and evaluated them avoiding problems in the future.

  • Advantage

This type of regimen offers the opportunity to achieve a very rapid weight loss.


The type of foods allowed are shallow in calories; they do not contribute sugars or fats to the body.

When there is no carbohydrate intake, the body uses fat reserve tissue for its metabolic functions

  • Disadvantages

Most of these diets are unbalanced, usually based on a single nutritious element: proteins in the diet of Dr. Atkins or hydrates and fats in the South Beach diet.

They are regimens that can only be followed for a short time due to their nutritional deficiencies.

Most of the weight loss is due to the elimination of liquids contained in the cells.

The foods recommended by these regimens provide very little caloric content.

Once the diet is finished, the rebound effect occurs.

They can cause kidney or liver problems, as in diets with high protein contents.

They do not modify the dietary habits that allow them to practice these regimes for a long time.

They can produce hypercholesterolemia since many diets recommend foods with high fats, such as the ketogenic diet.

Types of Fast Diet

There are balanced diets to reduce body weight, which are low in calories and are based on a combination of foods.

To provide the body with all the necessary nutrients that allow weight loss in a healthy way and without unwanted effects.

Others include fast diets, which are highly restrictive and are reduced in calories and most nutrients that the body needs to perform its metabolic functions.

These diets should only be followed in specific cases because they involve a risk of having the rebound effect.

Among these diets, we have:

Apple diet

The diet lasts only four days.

You can only consume liquids and eat the apple on the first day, either in juices or whole.

The other three days are included progressively: vegetables, proteins such as cheese, and soy, to introduce all the food sets in small quantities, with the apple as the primary food.

Liquid diet

The liquid diet detoxifies the organism, and all the foods consumed in liquid form do not accumulate in the intestines and are easier to digest.

This diet lasts five days, and all food will be consumed in juice, smoothie, cream, and puree, and both plant and animal origin foods may be consumed.

Diet 5-2

In this diet for seven days alternating five days of meals to taste, avoiding excesses, and two days in which a semi-fast is performed, in which the total of food eaten daily, should not be higher than 500 cal.

They can be eaten either in a single meal or distributed throughout the day. They should be consumed foods with low caloric content, but that gives the impression of satiety.


Most fast-diet regimens involve creams, pills, starvation, dietary supplements, and meal plans with shallow calorie content and devices.

Which cause adverse effects such as:

Gallstones, dehydration, malnutrition, electrolyte imbalances, headaches, irritability, fatigue, dizziness, constipation, menstrual irregularities, hair loss, and loss of muscle mass.