Intermittent Fasting Part 1- The Basics

Intermittent fasting is a form of dietary restriction where a person goes for a predetermined amount of time without eating any food. The idea behind intermittent fasting is that by restricting food our bodies will more quickly and efficiently tap our fat stores for energy. While glucose (sugar) from carbohydrates is our most direct fuel source, we burn fat for energy when glucose isn’t available (this is why the Keto diet works so well for fat loss). Our bodies burn fat for energy even more during times of food deprivation (fasting).

We all naturally partake in a form of fasting while we’re asleep at night, but the window for intentional Intermittent fasting can vary. Some popular approaches are:

·       Eating within a six to eight hour window per day and fasting for the rest of the 24 hours.

·       Eating regularly five days a week and limiting the other two days to one 500-600 calorie meal.

·       Longer periods without eating, such as 24, 36, 48, and 72-hour fasts.

Some intermittent fasting plans, such as the 6:18 hour pattern (eating for six hours, fasting for 18 per day) has shown positive results in the decrease incidence of disease such as cancer and obesity. (https://www.nejm.org/doi/full/10.1056/NEJMra1905136)

What are the potential benefits of intermittent fasting?

A study published in the New England Journal of medicine found intermittent fasting to have the following health benefits:

• Thinking and memory. Studies discovered that intermittent fasting boosts working memory in animals and verbal memory in adult humans.

• Heart health. Intermittent fasting improved blood pressure and resting heart rates and lowered bad cholesterol levels along with other heart-related measurements.

• Physical performance. Young men who fasted for 16 hours showed fat loss while maintaining muscle mass. Mice who were fed on alternate days showed better endurance in running.

• Type 2 diabetes and obesity. In animal studies, intermittent fasting prevented obesity. And, in six brief studies, obese adult humans lost weight through intermittent fasting. People with type 2 diabetes may benefit: Most of the available research shows that intermittent fasting can help people lose body fat and lower their levels of fasting glucose, fasting insulin and leptin while reducing insulin resistance, decreasing levels of leptin and increasing levels of adiponectin. Certain studies found that some patients practicing intermittent fasting with supervision by their doctors were able to reverse their need for insulin therapy.

• Tissue health. In animals, intermittent fasting reduced tissue damage in surgery and improved results

“Evidence is accumulating that eating in a 6-hour period and fasting for 18 hours can trigger a metabolic switch from glucose-based to ketone-based energy, with increased stress resistance, increased longevity, and a decreased incidence of diseases, including cancer and obesity”

https://www.nejm.org/doi/full/10.1056/NEJMra1905136

It’s important to remember that going too long without eating may actually encourage the body to start storing more fat if you are in an extreme caloric deficit. Make sure that you are eating sufficient calories during hours you are eating, and remember that intermittent fasting does not give free rein to eat whatever you want- always practice mindful eating and chose nutritionally dense foods.

Next week we will discuss scheduling fasting and strategies for intermittent fasting combined with strength training.