Fasting goes mainstream
Obviously, religious people and kooks have been fasting since forever, so why is it suddenly trending? If you’re like me, fads smell like trouble.
Background: History and animal studies
Back in the 1980s and 1990s U.S. studies looked at effects that reducing smoking had on heart disease risk. Interestingly, the risks seemed to reduce more in members of the churches of Latter Day Saints / Mormons than in other people.
Researchers wanted to know why, and that’s when they found a possible connection with fasting.
Beyond smoking, researchers started looking specifically at people who fasted.
In the early 2000s, they found that people who reported routine fasting (for religious reasons or not) had lower risk of heart disease. People who reported fasting had lower blood sugar levels, body-mass indices (BMIs), and risks of diabetes.
When it comes to animal studies, it’s easy to restrict when an animal eats, so there are a lot of studies on the health effects of IF in animals.
Animal studies show a lot of health benefits of IF including longer lives and reduced risk of atherosclerosis (narrowing of the blood vessels due to buildup of plaque), metabolic dysregulation (includes type 2 diabetes), and cognitive dysfunction (ability to learn, remember, solve problems). They also have lower levels of inflammation and generally live longer.
So, let’s dive into the health benefits of IF.
Intermittent Fasting for Weight and Fat Loss
For people who have excess weight, even if they seem to be in good health, losing weight and fat is associated with reducing the risk of diabetes, improves their healthy lifespan, and increases function of both the body and mind.
After about 5-6% of a person’s body weight is lost, even more health benefits are seen – lower blood lipids (LDL cholesterol and triglycerides), better blood sugar management (lower glucose and insulin), lower blood pressure, and lower levels of inflammation (C-reactive protein).
These benefits are seen with both calorie reduced diets and with IF.
When it comes to weight and fat loss, a typical calorie-reduced diet can work. By consistently reducing the amount ingested by 15-60%, people with overweight and obesity lose weight and fat. This is called “continuous” calorie reduction because one is continuously reducing what is ingested – at every meal and snack, every day.
Calorie reduced diets can include eating smaller servings, changing some foods eaten for low calorie substitutions, and/or cutting out some snacks/desserts every day.
By calorie-restricted eating is hard, and hard to maintain. The best weight loss diet is actually the paleo diet. Because it focuses on eating nutrient-dense foods, fibre-rich veggies, satiating fats, and muscle-building proteins, paleo is the best weight loss diet around. It is easier to feel full than on the calorie-reduced diet, and to be healthy while doing so.
However, not everyone likes cutting out empty calories and eating nutritious foods like game meat, broccoli, and liver, so those who love the pleasures of food may find both of the proven weight loss diets not worth the sacrifice. These people want to eat sugar, drink alcohol, and eat cheese sometimes. For these people, IF is a better option.
Intermittent fasting isn’t a continuous reduction, but rather an intermittent one. It allows you to eat what you want, but only during certain times. It’s an alternative to calorie reduced diets. IF is a way to “diet” without “dieting,” so to speak.
Both continuous calorie reduction and IF have similar weight loss results.
Intermittent fasting has a few key benefits!
Many studies prove what we know already: it’s really difficult to sustain a (continuous) calorie reduced diet for a long time.
This is the reason why many people prefer intermittent fasting – it gets similar weight and fat loss results, plus it’s easier for many people to stick with.
This makes IF a great alternative for anyone who wants to lose weight and fat, but has difficulty sticking with a reduced calorie diet.
Other advantages to IF over calorie reduced diets are that it can help people eat more intentionally (and less mindlessly). Also, some studies show that IF makes our metabolism more flexible so it can preferentially burn fat, while preserving the muscles. This is a great benefit because that can help improve body composition in people with excess weight.
In the next post on this topic, I will talk about specific ways the IF supports heart health.