The word fasting brings up my Catholic guilt.

In the early days of the church, like when I went, this fasting ritual existed at different times. It included, (so called) starving on Sunday mornings so we could partake of a little white wafer representing salvation while the other kids had pancake orgies. This moment of my childhood is not fondly remembered. It was sold as a way to save my soul, too esoteric a concept for this hungry 9-year-old boy. Defiantly, I dove into my secret Fruit Loops stash thinking that everything would work out.

So far so good.

So why would you want to re-examine this idea, especially from the side of science that says that fasting juices or using concoctions of any kind in place of food for long periods of time can be dangerous and unhealthy for many?

Because there is a new kid in town named Intermittent Fasting and much of the available science has good things to say.

There are at least 6 different styles developed by so many enthusiasts and a couple of doctors, each with a variation of when to eat, what not to eat, and how much. The effects range from fat and weight loss to better cognition and long-term disease prevention.

Let’s start with a little science on the physiology of fasting.

When we eat, the body goes into digestion mode. Insulin rises because blood sugar is produced by the digestion of such food. This will last between 3 and 5 hours. Once it has been fed and the food has been digested, it will be in post-absorption mode. This means that it has finished processing and absorbing nutrients. Insulin has dropped back to normal. Now enter fasting mode. The longer you stay here, the more likely your body is to burn stored fat for energy. However, if you spend too long here, your body will burn muscle and lower your metabolic rate as a way to preserve energy stores.

The key is to fast long enough, and is hotly debated for how long, to burn stored fat and give you the benefits of calorie restriction not to mention the drawbacks.

The simplest of these plans calls for eating within 8 hours (no matter what 8 hours) and fasting for 16. It might seem like you eat dinner at 8, skip breakfast, and eat again at 1.

The confusion has just begun. Isn’t it bad for you to skip breakfast?

For some it will be. If you have hypoglycemia, this is not the plan for you.

For others, the body will adapt, you will not die, and the results for those looking to lose weight can ruin the traditional diet.

Why is it mainly because it is easier to restrict the times you eat than the amount or what you eat.

There are other plans. Krista Varady’s Everyday Diet, a scientist, is popular and well-researched. You pretty much eat what it sounds like, every other day you fast or feast. An interesting finding from the research Krista has done is that most people don’t overeat enough on the day of the holiday to prevent weight loss.

Martin Berkhan originated the IF name and has a variety of options if you want to give it a try.

John Berardi of Precision Nutrition is, in his words, a professional dietitian. That is, he makes a living by trying diets and exercise programs. It has the best free download on the IF way of weight loss and health. You can grab it here. He tried almost every variation he could think of. Since exercise is still important, it refers to when to exercise within a period of time of fasting.

It is worth noting that his last word on whether it works for weight loss and is healthy or not is this: many programs will work if the person adapts and sticks to them. This is just one option.

There are extreme versions of this concept where you eat 500 calories one day and usually the next day or you eat one day and fast 2, and so on. I’m never a fan of extremes, not even as a launching pad for a plan. If it DOES sound like a good idea or you just want to try it and see how you feel and if you are going to lose weight, start by shortening the hours of the day that you will eat. As in the first scenario I described.

Other than the smaller thighs, what other good things happen?

Intermittent fasting falls into the category of calorie restriction, which has been well researched by science as a way to increase life expectancy.

Animal studies have supported FI as a bridge to better health and longevity and cautioned against it. Scientific America published a full article on this.

We are in the early days of IF science, but it’s hard not to believe the science that exists. If you try it, monitor how you feel when you are fasting. Don’t spend any more time than you feel safe, but prepare to feel hungry. Learning to feel real hunger versus the urge to eat out of boredom or anxiety is one of the benefits of IF.

Now that I am no longer forced to follow someone else’s rules about when I eat, or why, I am going to experiment with IF without feeling guilty or thinking for a minute that it will be my salvation.