The Nutrition Debate #83: “The 8-Hour Diet,” based on “brand new science”

On the Today Show on January 2^nd author David Zinczenco told host Matt Lauer that his new book, “The 8-Hour Diet,” described a way to lose weight based on “brand new science.”  My wife told me about this segment of the morning TV show, and so I searched the archives and played it back. I also found an excerpt from the book on NBCNews.com here.

When I asked my wife how it worked, she was a little vague, saying something about stomach shrinking… When I saw the re-play, I understood why. The author, with Lauer as critic and foil, showed lots of goodies: yoghurt, berries, orange juice and bran muffin for breakfast, a big salad, two slices of pizza, cup of soup plus potato chips or French fries for lunch, and a big rib eye steak with potatoes, veggies and a piece of chocolate cake for dinner. Lots and lots of comfort foods and no counting of anything: calories, carbs, protein or fat. This diet didn’t look like a diet at all! And it had eye appeal as well. Zinczenco described the diet as “lean protein, good fats, and complex carbs” – the current, politically-correct composition.

The only limiting factor was that all the food for any particular day had to be consumed within an 8-hour window: 9 to 5, 10 to 6, or even 11 to 7. The particular example given was 10:30 for breakfast, 12:30 for lunch, and 6:30 for dinner. The day starts with coffee or tea (black?) but no breakfast before work, the “breakfast” being eaten at a mid-morning break, and lunch and dinner at conventional times. Instead of the conventional breakfast at home, the author suggested a brief (under 10 minute) period of strenuous exercise to “turbocharge” (jump start) your metabolism and “get rid of the calories stored in your liver.” Translation: burn the stored carbohydrates, in the form of glycogen, in your muscles and liver – a pretty good idea actually.

The other “indulgence” the author offered is that you could do this 8-hour diet for only (“even just”) 3 days a week to lose as much as 5 pounds a week and 20 pounds in 6 weeks.  He tried it himself, he said, and lost 7 pounds in 10 days. He called this 3-day-a-week practice “intermittent fasting.” Known as IF, this is a common weight-loss practice. I did it recently for two days (after my weight drifted above “target”) and lost 7 pounds in two days while eating only a VLC breakfast (no-lunch or dinner and no snacks) for two days. It was mostly water loss but my body needed to get energy from somewhere so it burned fat (and muscle) to maintain my energy balance. This is not a good thing to do as a rule, but okay if you need a quick momentum shift.

David Mendoza, a well-known, low-carb Type 2 diabetic author, recently offered a similar “weight-loss tip.” He said that whenever his weight drifted above “target” (he describes his current weight as “low-normal,” which is truly enviable, if not skeletal), he skips dinner that day. He said he has only had to do that 9 times in the last 6 months).

So, I have to say this diet has obvious appeal for a “healthy” person with “normal” metabolism, which excludes anyone with any of the indications of Metabolic Syndrome (see #9 here). It is clever merchandizing to sell a book on the Today Show to an audience of women who aren’t the least bit interested in the mechanism or counting  – only in the eye-appeal of all their favorite foods and the comfort of not having to deny themselves anything except eating for 16 hours a day for three days a week. Zinczenco points out that that’s not so tough either, since most people already fast between dinner and breakfast. To stress this point he noted the word breakfast is composed of “break” and “fast.” He also spoke disparagingly of the practice many have today of “grazing all day long,” including sometimes after dinner. For three days a week, at least, that is a “no-no.” And if you’re still eating carbs, I like the idea of a brief strenuous exercise routine early in the morning to burn them up.

But what’s the real physiological mechanism of the 8-Hour Diet?  It works on the principle of the fed state and the fasting state, hardly a brand-new science. It is the basis of the hard scrabble existence of mankind on this earth from the beginning of the Paleolithic Era. You hunt, you eat, you rest while you digest, and then you burn stored fat while you hunt again when your hormones tell you that you need to eat again. Your body regulates this “harmonic ensemble” to maintain homeostasis, quoting ‘certain conclusion’ #2 from Gary Taubes’s “Good Calories-Bad Calories” (see The Nutrition Debate #5 here).And this cycle continued throughout life and for 500 generations, until the advent of the Neolithic Era 10,000 years ago. Agriculture introduced cultivated grains, grain storage, domesticated animals, and more-permanent human settlements.

The fed state echoes the time in the Paleo Era when, after eating, food is digested and absorbed. This is known as the glucogenic state since all carbohydrates and about half the protein we eat eventually becomes glucose, the latter through a process called gluconeogenesis. The fasting state begins when the glucose energy from the last meal has left the stomach and small intestine (where most of it is absorbed into the blood stream), and hormones switch the body to a ketogenic state. In a ketogenic state our bodies break down body fat (triglycerides) for energy. This state is also called ketosis because when the triglycerides are broken down to fatty acids and glycerol, they produce ketone bodies as a byproduct. Dr. Richard Veech of the National Institutes of Health says, “…ketosis is a normal physiologic state. I would argue it is the normal state of man.”

This natural state of ketosis occurs today every day between dinner and breakfast when we fast (>12 hours, if we don’t ‘snack’ after dinner). The 8-Hour Diet being promoted in this book just extends the nightly fast from 12 to 18 hours, 3 days a week.

© Dan Brown 1/12/13