Intermittent fasting is the process of cycling in and out of periods of eating and not eating.
Although people do experience weight loss with intermittent fasting, it is less of a diet plan and more of a lifestyle choice to reap a variety of health benefits.
There are different intermittent fasting methods. These are:
- 5:2: This method allows you to eat normally five days a week. The other two days are your fasting days, although you do still eat. Just keep it between 500 and 600 calories
- Eat-stop-eat: With this one, you restrict all food for 24 hours, once or twice a week.
- 16/8: You eat all of your daily calories within a shortened period — typically 6 to 8 hours — and fast for the remaining 14 to 16 hours. You can do this every day, or a few times a week.
When you don’t eat any food for a set period of time each day, you do your body and your brain a lot of good.
It makes sense from an evolutionary standpoint. For most of history, people were not eating three meals a day nor were they grazing on snacks throughout the day. Instead, humans evolved in situations where there wasn’t much food, and they learned to thrive when fasting.
There is a lot of incredibly promising research on intermittent fasting — highlights include weight loss; and reduction of blood pressure, cholesterol, and blood sugars. A growing body of research suggests that the timing of the fast is key, and can make intermittent fasting a more realistic, sustainable, and effective approach for weight loss, as well as for diabetes prevention.
Intermittent fasting makes intuitive sense. The food we eat is broken down by enzymes in our gut and eventually ends up in our bloodstream. Carbohydrates, particularly sugars and refined grains (think white flours and rice), are broken down into sugar, which our cells use for energy. If our cells don’t use it all, we store it in our fat cells — as fat.
Sugar can only enter our cells with insulin, a hormone made in the pancreas. Insulin brings sugar into the fat cells and keeps it there. Between meals, as long as we don’t snack, insulin levels will go down and fat cells can then release their stored sugar, to be used as energy.
We have evolved to be in sync with the day/night cycle, i.e., a circadian rhythm. Our metabolism has adapted to daytime food, nighttime sleep. Nighttime eating is well associated with a higher risk of obesity, as well as diabetes. Just changing the timing of meals, by eating earlier in the day and extending the overnight fast, significantly benefited metabolism even in people who didn’t lose a single pound.
There is evidence to suggest that the circadian rhythm fasting approach, where meals are restricted to an eight to 10-hour period of the daytime, is the most effective means of intermittent fasting.
Additionally, when you fast, several things happen in your body on the cellular and molecular level. First, the body adjusts hormone levels to make stored body fat more accessible. Also, cells initiate important repair processes and change the expression of genes.
Other changes that occur in the body with intermittent fasting include:
- Human Growth Hormone (HGH): The levels of growth hormones skyrocket, increasing as much as 5-fold. This has benefits for fat loss and muscle gain, to name a few.
- Insulin: insulin sensitivity improves and levels of insulin drop dramatically. Lower insulin levels make stored body fat more accessible.
- Cellular repair: When fasted, your cells initiate cellular repair processes. This includes autophagy, where cells digest and remove old and dysfunctional proteins that build up inside cells.
- Gene expression: There are changes in the function of genes related to longevity and protection against disease.
TAKE AWAY POINTS —
- We lose weight if we let our insulin levels go down. The entire idea of intermittent fasting is to allow the insulin levels to go down far enough and for long enough that we burn off fat.
- There is some good scientific evidence suggesting that circadian rhythm fasting, when combined with a healthy diet and lifestyle, can be a particularly effective approach to weight loss, especially for people at risk for diabetes.
- Changes in hormone levels, cell function and gene expression are responsible for the health benefits of intermittent fasting.
In summary, switching to an intermittent fasting diet expands your limits and boosts your performance in a number of ways. Here are some of the powerful benefits of intermittent fasting:
- Boosts weight loss
- Increases energy
- Promotes cellular repair and autophagy (when your body consumes defective tissue in order to produce new parts)
- Reduces insulin resistance and protects against type 2 diabetes
- Lowers bad cholesterol
- Promotes longevity
- Protects against neurodegenerative diseases such as Alzheimer’s and Parkinson’s
- Improves memory and boosts brain function
- Makes cells more resilient
People with advanced diabetes or who are on medications for diabetes, people with a history of eating disorders like anorexia and bulimia, and pregnant or breastfeeding women should not attempt intermittent fasting unless under the close supervision of a physician who can monitor them.