Ever see an ad for Instant abs now? The perfect body in days? Lose 30lbs in 2 weeks? Society gives us this unrealistic belief that the perfect body can be obtained in little to no time at all, but in reality that is not the case. It is important for us to understand that diets are life style changes, they do not magically work over night and cannot be something that is constantly started and stopped. Nowadays there are so many different types of diets that exist and rightfully so, as not each and everyone of us will respond to the same diet. Today we will be talking about intermittent fasting and the positives and negatives that come with this type of dieting.. or rather life style change.
Take Home/ Key Points
- Intermittent fasting (IF) is a flexible dieting program which controls when you can and cannot eat. For example only allowing yourself to eat for 6 hours of the day and fasting for the remaining 18 or fasting for 1 day of the week and eating normal hours the remainder. Different fasting regimes will be discussed in more detail below.
- IF can prevent or potentially reverse harmful and life threatening conditions such as diabetes, obesity and cardiovascular diseases
- IF programs are proven to decrease body weight and body fat
- alternate day fasting has shown the best research in terms of IF and reductions in body weight (3-7%), body fat (3-5.5kg), total cholesterol (10-21%) and triglycerides (14-42%) in normal weight, overweight and obese individuals.
- short fast between 18-24 hours have been proven to be beneficial in promoting triglyceride breakdown and fat oxidation. This increase in lipolysis (breakdown of fat) may cause an increase in fatty acid mobilization and utilization within adipocytes (fat storing cells) creating an overall increase in energy expenditure and aiding in the prevention and treatment of obesity. Basically there is an increase in fat breakdown and thus these fat molecules get used for energy in everyday activities.
- “fasting for 16-24 hour activates the stress-adaptation mechanism which offers protection against disease while eating 3-4 times a day prevents the response of adaptive mechanisms”
The term intermittent fasting is used to describe a diet or eating pattern which cycles between periods of eating and periods of fasting. This type of diet has no rules on what you can eat but rather looks at when you should eat. However being cautious of what you do eat will allow for the best results and outcomes. Studies on fasting have been conducted for decades and there is a significant amount of research which examines varying time periods of deprivation.
Although IF has been a term used more recently such eating patterns have been around for thousands of years and can been see by some as a more natural way to eat and consume food. If you think back to the time period of hunters and gathers it is safe to say that food was not always available. They did not have supermarkets, grocery stores, refrigerators or food available year round. Rather there were periods throughout the year where food was scarce and individuals had to function and evolve without food for extended periods of time.
It is important to note that the term intermittent fasting is a broad term used to describe various eating patterns and that there is not one rule that must be followed. Another important factor to mention is that although it is termed intermittent fasting, during the fasting periods one may choose to consume a minimal amount of calories (25% of daily intake, 300-500calories). The purpose of intermittent fasting is to improve body composition and overall health. The most popular protocols discussed and followed include: alternate day fasting, whole day fasting, and time restricted feeding. These protocols are illustrated in the chart below.
Short term fasting regimes have been shown to be beneficial and effective in terms of metabolic changes and these changes may be the basis for the benefits seen in individuals who follow an intermittent fasting program. During the fasting state there is evidence that shows there is a large switch in substrate utilization from carbohydrates to fatty acids. This change in fuel source can be seen as a major reason as to why so many benefits can arise from intermittent fasting protocols. Such benefits include a decrease in cholesterol, a decrease in triglycerides, and a decrease in total body fat and increase in lean body mass. Such changes in body compositions can reverse or prevent harmful diseases such as diabetes, high blood pressure, high cholesterol, obesity and cardiovascular diseases. In short term fasting regimes there have been results that have shown a decrease in glucose concentrations while an increase in whole-body lipolysis (fat breakdown) and fat oxidation particularly within the first 24 hours. This increase in lipolysis (fat breakdown) is thought to be a result of decreased concentration of insulin, increased sympathetic nervous system activity and a higher concentration of growth hormone in the blood.
We've explained multiple positive benefits to intermittent fasting, however like any other diet or life style change it takes patience, commitment and time. Results will not occur over night nor will the benefits that come along with it. Intermittent fasting is only one method of dieting and it does not always work for everyone. Like most things we have to experiment and try multiple different things until we find which works best for us. Today I gave you some information on intermitting fasting and the benefits that can arise from it, so if it is something you think could benefit you, give it a try! Tune in in the new year for more interesting topics.