Did you see this piece by the BBC? For those who are not members of the CR Society or livingthecrway, here is the four part video series that just aired:
Most media pieces on CR are riddled with mistakes. Here is my take on the BBC piece.
Paul
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The BBC recently released a special, hosted by Dr. Michael Mosley, "The Power of Intermittent Fasting." We appreciate Dr. Mosley's affable hosting of this program. It gives hope to millions that living long and healthfully is not only possible but that people are doing it right now.
Dr. Mosley visited the home of our friend, Joe Cordell, for a lesson in how he practices calorie restriction. From observing Joe’s large bowl of fruit each morning and perhaps other meals, Dr. Mosley concluded that he could not practice calorie restriction. This so often happens in personal interviews, where a very narrow idea emerges about what calorie restriction really is. On the other hand, we prefer breakfast to be a very large meal, loaded with vegetables and low GI grains and including some fruit and fish a few times a week. Most important, the food should be delicious and satisfying so it is fun!
After Dr. Mosley decided that he couldn’t practice CR, he began to explore the eating pattern of alternate-day fasting or intermittent fasting: having all you want on one day – or sometimes longer – and going without almost any food the next.
Dr. Mosley finally decided that he wanted to follow a 5:2 variation: eating "ad lib" for five days a week and eating only 600 calories for the other two days. Although Dr. Mosley’s voice narrated the point that limiting protein intake, too, is important for calorie restriction benefits to be achieved, he chose a very high protein diet for his "fasting days" – eggs and a small slice of ham in the morning, followed by fish with lots of vegetables in the evening. In the program, I also saw some strawberries on Dr. Mosley’s breakfast table. Here’s a macronutrient breakdown of how such a meal might look, as analyzed by the NutriBase CR Way Edition software that we use to check the content of our meals. Notice the percentages of macronutrients of such a meal plan:
Calories from fat: 44.20%
Calories from protein: 42.38%
Calories from carbohydrate: only 13.60%
Of course this is just a guestimate. Perhaps Dr. Mosley can provide more details.
Such a high fat, high protein diet would allow little tryptophan absorption through the blood-brain barrier – resulting in very low levels of serotonin, the neurotransmitter that helps control satiety in the hypothalamus. That would likely make calorie restriction – or any form of dieting – difficult and unpleasant.
Here’s more about the relation between tryptophan in the blood and macronutrients:
Effects of normal meals rich in carbohydrates or proteins on plasma tryptophan and tyrosine ratios.
Wurtman RJ, Wurtman JJ, Regan MM, McDermott JM, Tsay RH, Breu JJ.
Department of Brain and Cognitive Sciences, MIT, Cambridge 02139, USA.
American Journal of Clinical Nutrition. 2003 Jan;77(1):128-32
PMID: 12499331, NIH, NLM, PubMed access to MEDLINE biomedical citations
See the full abstract:
High protein intake might also inhibit activation of the sirtuin genes, which are important at the cellular level for calorie restriction benefits to be achieved. Sirtuins are NAD-dependent deacetylases, which means that to become active, they require a build-up of the energy-facilitating enzyme NAD. A primary pathway that makes NAD build-up possible requires the amino acid tryptophan: Tryptophan –> NAD –> Sirtuins 1-7.
In the program, Dr. Mosley mentioned that approximately 100,000 people are living the CR Way, worldwide. It turns out that the CR Way takes a very different approach to starting a calorie-restricted diet: Before people limit one calorie, they are encouraged to learn how diet and lifestyle choices affect emotions. Starter meals are suggested that increase neurotransmitters and other biochemistry that help people control cravings for comfort foods. You can find out more about it through this video of a presentation I made at the Dalman Symposium at the University of California, San Francisco.
I have been practicing calorie restriction happily for almost 20 years. However, if I chose the macronutrient ratio that Dr. Mosley did on his fasting days, CR would become difficult for me: I might want to give up CR. The film provides insights into conflicts that can arise when the brain biochemistry necessary for happy dieting seems to be in conflict with the rational knowledge that eating fewer calories will help us live longer and better.
Telling moments occur when we hear Dr. Mosley saying that he wants to avoid the problems of old age but can’t quite bring himself to follow a CR diet. The reality, though, is that the happiness biochemistry is not being taken into account. When it is, CR is easy and enjoyable.
This is important news for millions who want a healthful way to lose weight because it makes calorie restriction so much more doable.
The CR Society International and the CR Way very much appreciate the publicity that the BBC has given to calorie restriction. Now, we hope you will take it a step further and work with us to let the public know about the subtle dietary differences that make calorie restriction fun and easy to do.
