What if I tell you that all you need to do to lose weight is read the calendar and show the time? These are the basics for a successful diet with periodic fasting.
Could it be that simple? Does it work? And what is the scientific basis of starvation? As a registered nutritionist and expert in human nutrition and metabolismI am often asked such questions.
Simply put, periodic fasting determined by alternating established periods of fasting with periods allowed to be eaten. One method daily fasting. On “fasting days” proponents of this form of fasting are limited to consuming no more than 500 calories a day; in the “holidays” that occur through the day, they can eat freely, with no restrictions on the type or amount of food eaten.
Other methods include the increasingly popular ones Method 5: 2. This form of fasting includes five days of feasting and two days of fasting per week.
Another variation relies on time-limited nutrition. This means that followers should fast for a certain number of hours – usually 16 to 20 a day – and freely consume food for a certain period of four to eight hours.
To answer these questions, it helps to understand the basics of human metabolism.
Human metabolism 101
The The human body requires a constant supply of energy to sustain life, and the foods we eat provide us with that energy. But because eating is often followed by periods of time without food, there is a complex set of biological pathways to meet the body’s energy needs between meals.
Most pathways function at a certain level all the time, but they fluctuate after eating according to a predictable pattern called feeding cycle. The time frame of the cycle can vary depending on the type of food, the amount of food and the level of human activity.
This causes the release of insulin from the pancreas. Insulin helps the tissues of the whole body absorb it glucose and lipids that provide tissue with energy.
Once energy needs are met, glucose residues are stored in the liver and skeletal muscle in a condensed form called glycogen. When glycogen stores are full, excess glucose is converted to fatty acids and stored in adipose tissue.
About three to 18 hours after a meal – again, depending on a person’s activity level and food size – the amount of glucose and lipids circulating in the blood returns to baseline levels. Therefore, tissues should rely on sources of fuel that are already in the body, and these are glycogen and fat. A hormone called glucagon, which is secreted by the pancreas, helps facilitate the breakdown of glycogen and fat to provide the body with energy between meals.
Glucagon also triggers a process known as gluconeogenesis, which is the synthesis of glucose from non-dietary sources. It helps maintain proper blood glucose levels.
When the body reaches a state of true starvation – about 18 hours to two days without additional food – glycogen stores in the body are depleted, and tissues such as the heart and skeletal muscle, begin to depend heavily on fats for energy. This means increased breakdown of accumulated fats.
– Yeah! can be said. “So intermittent fasting is the key to ultimate fat burning?” Well, it’s not that simple. Let’s see what happens next.
Although many tissues adapt to the use of fats for energy, the brain and red blood cells need a constant supply of glucose. But when glucose is unavailable due to starvation, the body begins to break down its own proteins and instead converts them to glucose. However, because protein is also important for maintaining the body’s basic functions, it is not a sustainable process.
When the body goes into a state of starvation, the body goes into self-preservation, and there is a metabolic shift in an effort to save body protein. The body continues to synthesize glucose for those cells and tissues that absolutely need it, but the breakdown of accumulated fats also increases to provide energy to tissues such as skeletal muscle, heart, liver and kidneys.
That too promotes ketogenesis, or the formation of ketone bodies – molecules produced in the liver as an energy source when glucose is unavailable. In a state of starvation ketone bodies are important sources of energy because the body is not only able to use fat for energy. That’s why it’s inaccurate when some proponents of intermittent fasting claim that fasting is a way to burn “fat only” – it’s biologically impossible.
What happens if you break your fast? The cycle begins first. Glucose and lipids in the blood return to basal levels, and energy levels in the body are seamlessly maintained by switching between the metabolic pathways described earlier. The good thing is that we don’t even need to think about it. The body is well adapted to adapt between periods of feasting and fasting.
If the dietary approach is “all or nothing”. weight loss sounds appealing to you, chances are it might work. Indeed, periodic starvation has spawned clinically significant amount of weight loss. Periodic fasting is also possible reduce the risk of disease by lowering blood pressure and blood lipid levels.
In fact, weight loss caused by intermittent fasting is not due to spending time in some magical metabolic window, but due to a reduction in overall calorie intake. On holidays, people who are on a diet do not usually sit fully compensate for lack of food on fasting days. This leads to easy and moderate weight loss. Approximately 75% of the weight is fat mass; the rest is a lean mass. That’s about it the same ratio as the standard low-calorie diet.
If you still want to continue intermittent fasting, remember a few things. First, there are no studies on the long-term safety and effectiveness of following this type of diet. Second, studies show that intermittent fasting is not satiated certain nutrients.
Exercise is something else. It helps maintain muscle mass and can also help increase weight loss and long-term weight maintenance. This is important because almost a quarter of the weight lost on any diet is muscle tissue, and the effectiveness of periodic fasting for weight loss has been demonstrated only for a short time.
Also, once you stop following a diet with intermittent fasting, you will most likely regain weight. This is very important because many people find it difficult to follow a diet in the long run. Imagine the problem of planning a feast for six months and post around family dinners, holidays and parties. Then imagine doing it your whole life.
Ultimately, the best approach is to follow a diet plan that meets current dietary guidelines and fits into your lifestyle.
Citation: Intermittent fasting for you? Here is what science says (2022, May 19), received May 19, 2022 from https://medicalxpress.com/news/2022-05-intermittent-fasting-diet-science.html
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