Calorie restriction with adequate nutrition (CRAN)
Calorie restriction with adequate nutrition is a theory associated especially with Roy Walford, author of Beyond the 120 Year Diet. Walford did not associate his prescriptions with a Paleo perspective; however, some field testing of CRAN has been undertaken in a self-sufficiency context. That, and the supposition that early humans were likely to go hungry occasionally, have led those interested in palaeo foods to take a passing interest in CRAN. The latter rationale received an additional boost when a number of well-controlled lab tests indicated significant increases in longevity for laboratory mice fed a CRAN-type diet.
Professor Arthur Everitt (Univ of Sydney) has spent four decades researching the effect of restricted food intake on rats. He says we still don't understand how caloric restriction works, but the evidence is that it improves health across almost every measure: blood pressure falls, cholesterol falls, the rate of ageing of the kidney is reduced, the heart rate slows, ageing of collagen slows. Everitt emphasizes the importance of a nutritionally-dense diet (eliminating 'empty calories') (1).
Some diets (Like Ori Hoffmeckler's Warrior Diet) are basically one-meal-a-day diets and thus appear to have a CRAN aspect to them. Brad Pilon has written an e-book on brief intermittent fasts (2). Others have noticed that a low-carb diet, by significantly reducing hormonal hunger, makes it commonplace to forget to eat a meal in the 'breakfast, lunch and dinner' cycle common in the West; this, too builds on the idea of CRAN within a ~24-hour period. This would appear to be the most likely Paleo scenario, mixed in with occasional over-indulgence (simulating the discovery of a laden fruit tree in season, the killing of a large beast or number of fish or shellfish etc. in a fortunate hunt or a ceremonial feast).
(1) Fiona Carruthers, review article 'The Elixir of Youth' in Australian Financial Review Magazine, February 2004
(2) Eat Stop Eat - a book on the benefits of fasting for fat loss
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Page last up-dated 31 December 2009