The Critical Importance of Time Restricted Feeding in Weight Loss

Dr. Jason Fung
7 min readMay 30, 2018

There have been two main changes in dietary habits from the 1970s (before the obesity epidemic) until today. First, there was the change is what we were recommended to eat. Prior to 1970, there was no official government sanctioned dietary advice. You ate what your mother told you to eat. With the publication of the Dietary Guidelines for Americans, we were told to cut the fat in our diets way down and replace that with carbohydrates, which might have been OK if it was all broccoli and kale, but might not be OK if it was all white bread and sugar.

But the other major change was in when we eat. There were no official recommendations on this, but nevertheless, eating patterns changed significantly, and I believe contributed equally to the obesity crisis. From the NHANES study in 1977, most people ate was 3 times per day — breakfast, lunch and dinner. I grew up in the 1970s. There were no snacks. If you wanted an after school snack, your mom said “No, you’ll ruin your dinner”. If you wanted an bedtime snack, she just said “No”. Snacking was not considered either necessary or healthy. It was a treat, to be taken only very occasionally.

By 2004, the world had changed. Most people were now eating almost 6 times per day. It is almost considered child abuse to deprive your child of a mid-morning snack or after school snack. If they play soccer, it somehow became necessary to give them juice and cookies between the halves. We run around chasing our kids to eat cookies and drink juice, and then wonder why we have a childhood obesity crisis. Good job, everybody, good job. Without any science to back it up, many nutritional authorities endorsed eating multiple times per day as a healthy practice. There were no studies that remotely suggested this was true. It was likely the successful efforts of snack food company advertising to dieticians, and doctors, clueless about nutrition at the best of times, who simply went along for the ride.

This was not merely an American phenomenon. More recently, China has followed in America’s footsteps with increased snacking. Large scale surveys show that from 1991 to 2009…

Dr. Jason Fung

Nephrologist. New York Times best selling author. Interest in type 2 diabetes reversal and intermittent fasting. Founder