In developed and developing countries, individuals typically eat three meals a day for their daily energy intake. The amount of energy we need daily varies depending on our daily physical activity status, age, gender and disease status. The fact that the energy we take in is more than the energy we spend and the combination of sedentary life paves the way for obesity and the chronic diseases it brings (non-communicable chronic diseases such as type 2 diabetes, cardiovascular diseases, cancer). Considering all these, it is noteworthy that the prevention and treatment of obesity is very important. Weight management approaches in the treatment of obesity; It includes a variety of lifestyle interventions such as diet, physical activity and psychological elements to change unhealthy behaviors, promote weight loss and prevent weight gain. Diet and behavior modification therapy are the main issues that should be emphasized in the treatment of obesity. As a result of nutritional therapy having an important place in the treatment of obesity and its accompanying complications, different diet models have been developed. The one we have heard about most recently is the intermittent fasting (IF) diet, known as intermittent fasting in our country. However, this diet can deviate from its purpose and turn into a method abused by people who want to lose weight, and therefore its effect on human health is a matter of debate.
The survival and reproductive success of all organisms depends on their ability to obtain nutrients. However, they have developed behavioral and physiological adaptations that enable them to survive during periods of food deprivation. Mammals have liver and adipose tissue that function as energy stores during fasting of varying lengths depending on the species. It has been stated that the metabolic, endocrine and nervous systems develop in ways that provide high levels of physical and mental performance during the fasting state.
Intermittent fasting involves a nutritional cycle consisting of successive eating and fasting periods. The important factor in this diet is not the type of food eaten, but the time of eating. In this type of diet, planned meals are skipped and people stay hungry for more than the time allocated to nutrition. . Intermittent fasting diets basically include alternating fasting, time-restricted eating and religious fasting. All of these models have periods of fasting and eating on a daily or weekly basis. During fasting periods, no food except water is consumed. Alternating hunger; It consists of feeding days, in which foods are consumed as much as desired, at the desired time, and fasting days, in which individuals consume 25% of their energy needs. Intermittent energy restriction is achieved by periods of intermittent food intake based predominantly on very low-energy diets. Very low energy diets contain energy of 800 or less kcal/day and are not recommended for longer than 12 weeks in the treatment of adult obesity. These are alternating fasting diets that include the 5:2 diet, which is the starting point of intermittent fasting diets. This type of diet; It includes five days of regular nutrition, two days of <500 kcal/day energy intake for women and <600 kcal/day energy intake for men. The term time-restricted diet represents an eating pattern in which food intake is restricted to 8 hours or less each day. Religious fasting means abstaining from eating and drinking between dawn and sunset for a month (29–30 days).
Although studies on three different intermittent fasting diets show quantitative differences depending on the diet model and the species studied, all intermittent fasting diets; It leads to some basic metabolic changes such as maintaining low or normal blood glucose levels, depletion or decrease of glycogen stores, mobilization of fatty acids and formation of ketones, decrease in circulating leptin and increase in adiponectin levels. Both the increase in metabolic ketone use during the fasting period and the adaptation responses of the brain and autonomic nervous system to nutrient deprivation play an important role in the health-promoting and disease-preventing effects of intermittent fasting diets. The extent to which total energy restriction mediates physiological responses, as total energy intake is generally reduced during intermittent fasting diets It is thought that it is important to know.
Alternating Fasting
Alternating fasting is an innovative diet approach that can reduce body weight by 4-8% after 8-12 weeks. It includes fasting days, in which individuals consume 25% of their energy needs, alternating with feeding days, in which food is consumed as much as desired, at the desired time. As a result of the studies, it has been determined that alternating fasting reduces blood glucose and insulin levels, reduces total plasma cholesterol and triglyceride concentrations, and has beneficial effects on cancer risk factors such as cell proliferation. It was determined that in mice subjected to alternate fasting, there was a decrease in fat mass, especially in visceral fat, while lean body mass was preserved. In a study, the weights of the case group that underwent alternating fasting and the control group that consumed as much as desired at any time were found to be similar, but significant differences were detected in glucose metabolism and fatty acid mobilization. In those subjected to alternating fasting, glucose and insulin levels were found to be low, while hydroxybutyrate levels were high. It has been stated that alternating fasting reduces leptin levels as well as circulating insulin. In a randomized controlled study in 2013 in which alternating fasting was applied to healthy and overweight individuals for 12 weeks, it was determined that the average weight loss was 6% and it was shown that alternating fasting was an effective strategy for weight loss. The most well-known of this type is the 5:2 model. This type of diet; It is to eat regularly for five days, get 500-600 kcal of energy on 2 non-consecutive days of the week, and continue the normal eating pattern on the other days.
Time-Restricted Nutrition
Time The term restricted diet includes a diet in which food intake is restricted to 8 hours or less each day. In this method, a 16-hour fast is performed by skipping breakfast and eating in the remaining 8 hours of the day (For example, consuming food between 11 a.m. and 7 p.m., but not consuming any food at other hours). This eating pattern affects circadian clocks. k regulates metabolic functions. In a meta-analysis study, time-restricted feeding in mice not only increased insulin sensitivity; It was concluded that it was associated with decreases in body weight, total cholesterol, triglyceride, glucose, insulin, interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α). In a meta-analysis study conducted on humans, food consumption was observed at intervals of 3-4, 7-8 and 10-12 hours for time-restricted nutrition, and it was determined that the decrease in body weight was consistent and significant in the group of individuals who consumed food at intervals of 10-12 hours. It has also been noted that changes in body weight, total cholesterol, triglyceride, glucose, insulin, IL-6 and TNF-α, and insulin sensitivity are similar to animal studies.
Religious Fasting (Ramadan Model)
Fasting means abstaining from eating and drinking between dawn and sunset for a month (29–30 days). A change is observed in the timing and composition of food intake. The diet includes one meal just before dawn and one meal after dark in the evening. On average, there is a 9-20 hour fast. This nutritional model, which does not include any energy restrictions, may cause changes in metabolism due to the decrease in the frequency of food and liquid intake. Skipping lunch and long gaps between meals; It affects appetite, hormonal responses to food, and energy and glucose metabolism. In particular, not eating breakfast has been shown to be associated with a low thermogenesis induced by exercise, and it has been found that there is a decrease in insulin and glucagon-like peptide1 secreted in response to food in individuals with diabetes. In a meta-analysis study examining the weight change of individuals during the month of Ramadan; It was determined that there was a statistically significant weight loss of 62% with this nutritional model, but it was stated that this weight tended to be regained shortly after the month of Ramadan. In addition, negative changes in the circadian rhythm, its inability to apply in cases of chronic disease, and its difficulty in sustainability make this nutritional model a necessity. In addition to all their positive effects, it has been suggested that intermittent fasting diets also affect the microbiota due to their effect on circadian rhythms. Studies show that changes in the composition and metabolic functions of the intestinal microbiota in obese individuals can alter intestinal permeability and bacterial translocation that is a factor in the development of systemic inflammation, which is a marker of obesity-related diseases.
In addition to its positive effects, it should also be noted that intermittent fasting diets have negative aspects. . If we take a look at these:
-
Studies have shown that the glucose metabolism of hypercholesterolemic (low-density lipoprotein receptor deficiency) mice is negatively affected by intermittent fasting.
-
While glucose tolerance increased in rats that were alternately fasted for 1 month, impaired glucose tolerance was detected in rats that were alternately fasted for 8 months.
-
Most of the studies have small samples and short follow-up ( <6months). Studies indicating the long-term effects of intermittent fasting diets are necessary.
-
It has been stated that data on intermittent fasting diets do not have sufficient power to show the preservation of lean body mass.
-
It should also be noted that this diet is not applicable to every individual. It has been determined that individuals with normal weight and normal body mass index have low sustainability of intermittent fasting diets.
-
It has been stated that they have difficulty in carrying out their daily routine activities during the restriction days of the intermittent fasting diet
-
In addition, there are insufficient studies showing that intermittent fasting diets prevent weight gain in individuals with normal body weight and normal body mass index.
As a result, obesity If we look at this popular diet approach used in the treatment of cancer and associated comorbidities, there are animal and human studies showing that it has many positive effects, as well as its negative aspects. Current work
Read: 0
