Intermittent Fasting: Eating Pattern Rather Than a Diet
Currently, intermittent fasting — an eating pattern that cycles between periods of prolonged fasting and eating — is a popular health trend.
Adherents include those attempting to lose weight, improve their health, and simplify their lifestyle.
Many studies show intermittent fasting can have powerful effects on your body and brain and increase metabolism. Some believe that it can help you live longer. As a dietary method, it does not specify what foods you should eat, but rather when you should eat them. In this respect, it is more accurately described as an eating pattern rather than a diet. Fasting has been practiced throughout human history. Ancient hunters and gatherers did not eat three meals every day with snacks. They essentially followed intermittent fasting, because food was scarce and they did not know the next time they would eat. Fasting is still used for medical, religious, or spiritual reasons by millions worldwide.
The New England Journal of Medicine recently published a review on the current clinical data regarding intermittent fasting, which offers an overview of the health benefits and surveys various fasting regimens. This article briefly discusses those findings. Keep in mind that research is still in its infancy. Many studies have been conducted over the years on animals and humans, but the sample sizes are small and studies short-term. The long-term effects of intermittent fasting still remains to be seen.
Intermittent Fasting Methods
There are several different ways to approach intermittent fasting. All of the methods involve splitting the day or week into fasting and eating periods. During fasting periods, you eat nothing at all (or very little) but are able to drink water, coffee, tea, and other non-caloric beverages.
The 16/8 method: This involves skipping breakfast and restricting your daily eating period to 8 hours during the day, such as 11 a.m. until 7 p.m. Then, you fast for 16 hours. Those who are newer to intermittent fasting may consider fasting for a period of 10-12 hours as a starting point.
Eat-Stop-Eat: This involves fasting for 24 hours, once or twice per week. For example, you would not eat from dinner one day until dinner the next day.
The 5:2 method: With this method you only consume 500-600 calories on two non-consecutive days of the week, but eat normally the other 5 days.
By reducing your caloric intake, all of these methods should lead to weight loss, as long as you don’t compensate by consuming significantly more during the eating periods. It is important to fuel your body with healthy foods during the eating periods. Many people find that the 16/8 method is the most sustainable and easiest to follow. It is also the most popular.
If you are overweight or obese, fasting is an effective weight loss method if you adhere to it. In research studies, its weight reduction impact is similar to reduced-calorie diets. There are many other benefits associated with intermittent fasting not seen with reduced-calorie diets. When you fast, several things happen in your body. Your body will adjust hormone levels to make stored body fat more accessible for energy. During periods of fasting, you slowly burn through the glucose stored in the liver. The liver holds roughly 700 calories of glucose. It takes 10-12 hours to use the liver’s glucose/energy stores, then your body uses fat for energy. Insulin sensitivity improves, which leads to lower levels of insulin and renders fat more accessible for energy. Growth hormone levels significantly increase, resulting in benefits for fat loss and muscle gain. Cellular repair processes are initiated during periods of fasting. Studies have also shown reduction in blood glucose, blood pressure, cholesterol, and stress hormones. These are all risk factors for heart disease. Intermittent fasting has been shown to suppress inflammation markers, key drivers of many chronic illnesses. It may even improve brain health and memory. In animal studies, intermittent fasting extended the life span in rats. The rats in the fasting group lived 40-80 percent longer than control subjects.
Intermittent fasting is not safe for all people, including pregnant women, children, people at risk for hypoglycemia, or people with certain chronic health issues. Some people have a better response to fasting than others. It is simply one of many lifestyle strategies that can improve your health. The best diet is one that can be maintained long-term.
Participants must keep in mind that intermittent fasting does not give them a license to eat whatever they want. Do not expect immediate results: it can take a few weeks for the body to adapt to a point at which you see reduction in weight and improved health indicators. If you find yourself feeling overly hungry, fatigued, or irritable you may want to adjust your eating/fasting regimen. It is good to start slow to see if this is a good fit for you and your body. And of course, before starting any new lifestyle regimen, it is best to consult with your healthcare provider or dietician.
Tanya Munger | DNP, FNP-BC