WHAT IS IT?
Intermittent fasting is a pattern of eating that has been proven to be highly effective in burning fat with a variety of other health benefits. In terms of weight loss, studies have shown that intermittent fasting directly caused weight loss of 3-8% over a period of 3-24 week whilst retaining muscle mass and strength. Furthermore, people lost 4-7% of their waist circumference, meaning that they were burning belly fat which is often the hardest to remove. It might seem unusual to diverge from our traditional breakfast, lunch and dinner but it is in fact closely aligned with our natural evolution where there was great volatility with food supply and therefore brought upon frequent fasting.
Fasting can be defined as any period of time where food is not being consumed. This means that all of us have at least fasted during our periods of sleeping to whenever our first meal is. The most popular form of intermittent fasting is the 16/8 method, which gives an 8-hour window to eat and 16 hours of fasting i.e. last meal at 8pm and eat first meal the next day at midday. In a modern day setting where life becomes so fast-paced that you rarely have time to sit down for a meal, intermittent fasting integrates very well.
You might be thinking it is impossible to go throughout the day without eating anything, but surprisingly, intermittent fasting reduces hunger. This is because leptin, also known as the satiety hormone, helps signal to the body when it is time to stop. Leptin is produced in the fat cells and therefore, the more fat you have, the higher the leptin circulating in your body. However, high amounts of leptin can cause your body to become leptin-resistant and therefore increase the difficulty of turning off hunger cues.
A study with 80 participants measured leptin levels overnight during the “fasting” period and found it to be significantly lower than what it was during the day. Therefore, lower levels of leptin can translate to less leptin resistance (less hunger), which then translates to real weight loss.
For it to be most effective, during that 8-hour window, ensure that you eat a high-protein low-carbohydrate diet. More on that in a future blog post.
WHY DOES IT WORK?
Every time we ingest food, our insulin levels rise which helps store excess energy in two separate ways. It first stores glycogen in the liver, however, once that is saturated, the excess energy is stored as fat. In one study doing the 16/8 method, intermittent fasting caused a 12% decrease in blood sugar and almost 53% decrease in insulin.
Conversely the process is reversed during our fasted state where insulin levels fall, which then triggers the body to first start burning leftover glycogen. Once those limited reserves are exhausted, the body starts to burn body fat.
Therefore, the longer our fasted state, the more fat will be burnt. Beyond that, by simply reducing the time window in which you eat, you will naturally reduce your caloric intake.
Apart from the effective fat burning results, intermittent fasting has been shown to have a host of health benefits including:
Improved heart and brain health
Reduced risk of disease
In fact, in a study conducted by the USC, 71 adults fasted for 5 days in 1 month, eating anywhere between 750 – 1100 calories for those days. The results were exciting with the test subjects having reduced cardiovascular risk factors, inflammation levels, waist circumferences and total body fat but not muscle mass.
This is because intermittent fasting acts as a mild stress upon the body which causes it to increase cellular defences, therefore, guarding against the incorrect assembly of molecules. Furthermore, studies have shown it increases levels of a protein called brain-derived neurotrophic factor (BDNF) that prevents stressed neurons from dying. Diseases such as Alzheimer’s and depression have commonly been associated with low levels of BDNF. On top of that, it increases the process of autophagy (literally self-eating), which means that your body creates membranes that remove all dead, diseased or worn-out cells which prevents a host of neurological diseases.