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Why I Fast: A Nutritionist’s Approach to Fasting for Health

by | Nov 20, 2020 | +STORIES

When I first started learning about nutrition, I was told that in order to “fuel” the metabolism the ideal eating pattern was to eat 3 meals and 1-2 snacks a day. The goal was to eat every 2-3 hours so that you could consistently feed your metabolism, never get hungry, and prevent overeating. 

Like a good nutrition student, I tried this myself. I ate three meals and two snacks, even if I wasn’t hungry. After a week or two of doing this, I noticed the scale went up a couple of pounds. This was confusing to me, since I didn’t think I was overeating, but I was forcing myself to stick to a “schedule” no matter what.

Based on my personal experience, I felt something was off about this recommendation. Once I became a Registered Dietitian, instead of recommending this eating pattern to my clients, I started to encourage them to eat the snacks only if they were hungry. This seemed to make more sense and left them in control of their own eating patterns. 

Ancestral Nutrition

A few years into my career was the rise of the “Paleo” diet movement. Although I don’t fully embrace everything that paleo stands for, I was deeply involved in this community and way of thinking about diet. I do believe we should eat real, whole foods and reduce processed foods, one of the foundations of Paleo.

For the first time, I also came across the theory that the body and the digestive system needed periods of “rest” between meals. The “rest” periods are required to help insulin (a storage hormone) decrease enough to allow the body to actually use up stored energy or fat. If your insulin is constantly high, your body is constantly in storage mode, making it difficult to lose weight. 

This obviously completely flipped the idea of 5 small meals on its head. We needed to eat less often, not more often, to allow our hormones to naturally ebb and flow. 

Once I discovered the need for metabolic rest, I started recommending that clients only eat every 4-5 hours, unless they were very hungry. I also follow this myself. Rather than adding in a snack between meals, I recommend trying to eat more protein with meals to help stretch out the number of hours.

Intermittent Fasting

More recently, intermittent fasting (IF) has entered the popular diet scene. Although I had previously read about the benefits of fasting for longevity, it wasn’t until I was asked to write an article about it that I started to understand more. 

This initial article was based on a quote by geneticist Frances Ashcroft, who said that if we all fasted one day a week we could significantly reduce obesity and the risk of type 2 diabetes.[1] This quote from Dr. Ashcroft piqued my interest in learning more about the research behind fasting.

Began to learn about autophagy and the reduction of disease that could occur with implementing a simple fasting period into your day. This was of particular interest to me, as my mother died from breast cancer and I am always looking for ways to decrease my risk.[2] The simplicity of using it as a weight-loss method was also appealing since that has been a concern for me in recent years.

Overall, in my professional opinion, allowing periods of rest for your body and digestive system is a simple way to improve your health and help manage your weight.

How I Practice Fasting

The more extreme fasting practices that require more than fasting overnight do not work for my current lifestyle. I am a busy mom and business owner and can’t afford to have energy slumps during the day. 

For me, the simple rule of not eating after dinner (we eat early at 5 pm) and then extending that fast until after my morning workout puts me at about a 15-16 hour daily fast. I am not perfect about this protocol, I may not fast quite as long on weekends or if dinner is later in the evening.

Implementing this simple fast helped me lose baby weight after my last child and has helped me maintain the weight I lost. I am overall a healthy eater and for many of us the calories we mindlessly consume after dinner are what get us in trouble when it comes to weight management. 

I think fasting is a simple approach to better health and a fairly effortless weight management strategy. Although I have not experimented with longer fasts, simply not eating after dinner and slightly extending breakfast has been beneficial for me.

Read More:

[1]  Don’t Eat One Day a Week 

[2] Effect of Fasting on Health, Aging, and Disease


Ana Reisdorf, MS, RD, CDE


Ana Reisdorf has 13 years of experience as a Registered Dietitian and freelance writer. She has a passion for creating incredible health and nutrition content. She is the author of three books, the “The Lupus Cookbook”, “The Anti-inflammatory Diet One Pot Cookbook.” and the “21-day arthritis diet plan”. Find her at