Review of the Diet: Intermittent Fasting for Loss of Weight

Describe it.

A diet plan known as intermittent fasting alternates between short fasting intervals during which the dieter consumes little to no calories or much less than usual. It is marketed to alter body composition via weight loss and a reduction in body fat, as well as to enhance disease-related health indicators including blood pressure and cholesterol levels. Its origins may be traced back to traditional fasting, a global practice recorded in the early writings of Socrates, Plato, and religious organizations as having physiological or spiritual benefits. [1] A normal fast lasts anything from 12 hours to a month and involves a consistent abstention from food and drink. It may call for total abstention or permit just a limited intake of food and drink.

Very low calorie diets that are followed for an extended period of time may result in physiological changes that lead the body to adjust to the calorie restriction and stop further weight loss. [2] Intermittent fasting is an effort to solve this issue by alternating between periods of reduced calorie intake and periods of regular eating, which may stop these adaptations. However, studies do not consistently demonstrate that intermittent fasting is more effective for weight reduction than ongoing low-calorie diets.

What It Does

The most popular techniques include fasting on alternating days, for full days on a regular basis throughout the week, or for a predetermined amount of time.

Alternating days with no dietary restriction with days that only consist of one meal that supplies around 25% of daily caloric demands is known as alternate-day fasting. For instance, alternate days have no dietary restrictions whereas Monday through Friday are dedicated to fasting.

Whole-day fasting is when a person goes without eating for the whole day one to two days a week, or up to 25% of their daily caloric requirements. The 5:2 diet plan, for instance, encourages no dietary restriction five days per week, alternated with a 400–500 calorie diet the other two days.

Time-restricted eating entails adhering to a daily meal schedule and a set fasting window. Example: Meals are consumed from 8am to 3pm, while the rest of the day is spent fasting.

in the study So Far

Calorie restriction has been shown physiologically in animals to prolong life and enhance tolerance to a variety of metabolic stressors. [4] Although there is significant support for calorie restriction in animal research, the data in human studies is less compelling. Diet proponents contend that the stress of sporadic fasting triggers an immunological response that heals cells and results in favorable metabolic changes (reduction in triglycerides, LDL cholesterol, blood pressure, weight, fat mass, blood glucose). [3,5] It seems sense to worry that people who follow this diet would eat too much on days when they aren't fasting to make up for the calories they lose while fasting. Comparing this to other weight reduction strategies, research have not shown that this is the case.

Intermittent fasting was helpful for weight reduction, with a mean loss of 7 to 11 pounds over 10 weeks, according to a comprehensive assessment of 40 research. [2] The investigations were very variable, with subject counts ranging from 4 to 334 and lengths of follow-up from 2 to 104 weeks. It is significant to highlight that various research designs, techniques for intermittent fasting, and participant characteristics were used (lean vs. obese). The other half of the research focused on an intermittent fasting group alone. The first half of the studies were controlled trials that compared the fasting group to a comparison group and/or a control group (either continuous calorie restriction or regular lifestyle). An overview of their results is as follows:

Dropout rates varied between 0 and 65%. There were no discernible differences in dropout rates between the continuous calorie restriction groups and the fasting groups. Overall, the analysis found that intermittent fasting had a higher dropout rate than other weight reduction methods, therefore it was not necessarily simpler to follow.

There was no discernible difference in the amount of weight loss or changes in body composition between the fasting group and the continuous calorie restriction group in the 12 clinical studies.

Even while the intermittent fasting groups saw considerable weight loss and drops in leptin hormone levels, 10 studies that looked at hunger alterations did not reveal an overall increase in appetite in those groups (a hormone that suppresses appetite).

Intermittent fasting was not shown to be more efficient than daily calorie restriction in a randomized controlled experiment that tracked 100 obese people for a year. The American Heart Association recommended either daily calorie restriction (75% of baseline calories divided over three meals) or an alternating day fast (alternating days of one meal of 25% of baseline calories versus 125% of baseline calories divided over three meals) for the six-month weight loss phase. With the goal of maintaining weight, calorie intake was raised by 25% in both groups after six months. The majority of the participants in each group were women, and they were all typically in good health. The experiment looked at cardiovascular risk factors, compliance rates, and weight changes. Comparing the two groups' results, they found:

There were no notable alterations in body composition, weight increase, or decrease (e.g., fat mass, lean mass).

There were no significant variations in fasting insulin, fasting glucose, or blood pressure. The alternate-day fasting group had substantially higher LDL cholesterol levels at 12 months, despite there being no changes in total cholesterol or triglyceride levels. The authors made no mention of a potential reason.

The alternate-day fasting group had a greater dropout rate (38%) than the daily calorie restriction group (29%). Interestingly, the fasting group consumed more calories than recommended on fasting days while eating less than recommended on non-fasting days.

Intermittent fasting (16:8 technique) was not shown to be more advantageous than calorie restriction without a limited eating period in a one-year randomized experiment. Patients with obesity were assigned to a modest calorie restriction but were randomly assigned to either the time-restricted eating group (allowed to eat from 8am to 4pm) or the anytime eating group. Measurements included weight, waist size, body mass index, body fat, and blood work. At a year, the time-restricted group lost an average of 18 pounds, while the time-unrestricted group lost 14 pounds. Blood pressure, cholesterol, and blood sugar levels similarly dropped in both groups. However, there was no discernible difference between the groups in the weight changes or other metrics.

Possible Mistakes

Someone who eats often might find it challenging to follow this sort of food regimen (e.g., snacks between meals, grazes). Additionally, it would not be suitable for those with medical disorders that need for regular dietary intake because of metabolic changes brought on by their drugs, such as diabetes. When food is reintroduced after prolonged periods of food restriction or semi-starvation, one is at danger of overeating and harmful habits, such as an increased preoccupation on food, may develop.