Voluntary fasting is a practice that is based on the elimination of solid foods from the diet, reducing caloric intake to a maximum of 300 kcal. daily from liquid food. For religious or cultural reasons, fasting is a practice that takes place thousands of years ago, however, today it has gained special popularity along with other food fads, such as detox diets , that promise to “purify” or cleanse the body of toxins.
In the case of fasting, some studies tested on animals ensure that intermittent fasting can be healthy, reducing insulin levels and blood pressure, however, as Pablo Saz Peiró, a naturopathic doctor who defends this practice, recognizes in his research Intermittent fasting (Universidad de Zaragoza, 2016), a “few randomized controlled trials and observational clinical studies support the existence of a health benefit from fasting, but more additional research is needed”.
Laia Gómez, dietitian-nutritionist at Alimmenta assures that fasting “is not a necessary or useful or recommended practice”, which can also cause kidney and liver problems, for people suffering from pathologies of this type or diabetes.
When and how can we fast
Another myth about fasting is that it helps weight loss , but, according to the specialist, it is not true. “Probably if you fast for a few days you lose a kilo, but it is not a representative loss since it will be basically water and muscle glycogen that you will recover by hydrating again and eating,” he warns.
The dietician explains in which only fast can be prescribed is when we want to improve sports performance in endurance and long distance exercises. According to Gómez, training two or three days a week on an empty stomach can increase the amount of intramuscular triglycerides (fat in the muscle), which will serve to obtain energy during sports in moments of less intensity. In any case, the dietitian remembers that for the general population or short-term sports it will not be useful ”.
To do it correctly, Gómez explains that it must be done in the hours before training and only carbohydrates should be suppressed , being able to consume the rest of the nutrients.
“After the last training, you should not consume carbohydrates or recovery shakes, isotonic drinks, or fruit, so as not to regenerate muscle glycogen,” says the expert. Instead, you can consume vegetables and proteins such as meat, fish, and eggs. Once fasting resistance training is complete, we can restore carbohydrate intake.
Finally, Gómez remembers that if you decide to fast, it is important to constantly hydrate yourself and be aware of certain symptoms that could be indicating that it is time to abandon it: halitosis, dizziness, headache, nausea, vomiting, dry skin, dizziness, weakness, vision problems… our health can be altered with fasting
