The new BBC Special features Dr. Michael Mosley in Eat Fast Live Longer. He has inspired lots of people try intermittent fasting. And some swear by it, saying it’s a way to lose weight that they can tolerate. Others say it’s just as health-enhancing as calorie restriction. We disagree.
When you practice calorie restriction regularly, the body reduces its insulin production to adjust to your food intake. Long-term calorie restrictors have greatly reduced fasting insulin. The pancreas shifts to production of glucagon, the hormone that keeps energy available to cellswhen food is limited. Along with glucagon, wonderful things begin to happen: Excess body fat is burned; and the heart, brain, and other organs grow more energy-efficient and protected from diseases.
In contrast, intermittent fasting jerks the body around. You may do with little food for a few days and then gorge on the next. While little insulin is needed for the low-calorie days, your body gets a huge surprise on the days when you eat full meals. The pancreas and insulin production have a difficult job on the full-calorie days and so do cells that may have started to become energy-efficient on the fasting days – only to be overwhelmed with food on the full-calorie days.To take advantage of the importance of time away from food, the CR Way uses Daily Intermittent Fasting as a balanced way to work the benefits of a fast into your diet. You get extraordinary benefits of fasting plus the benefits of letting your body adjust to a regular routine. After all, fasting benefits are not so dependent on how much time you spend without food: The biochemistry that’s expressed during the fast is what is important.
The CR Way Daily Intermittent Fasting meal plan keeps glucose levels low while you eat. So when you start your daily fasting period, your glucose levels are likely to be low already. That means the cognitive and neuroprotective benefits of ketones will arrive much faster than if you practice intermittent fasting with excessive calorie intake on certain days that likely leaves you with very high glucose for the start of your fast. It will take hours or days to work that glucose level down to a healthy place.
These excerpts from a related forum post,explain more about fasting benefits. It provides background on why and how we developed Daily fasting. We provide it here for continuity.
Mattson MP, Duan W, Guo Z.
Journal of Neurochemistry. 2003 Feb;84(3):417-31.
Although all cells in the body require energy to survive and function properly, excessive calorie intake over long time periods can compromise cell function and promote disorders such as cardiovascular disease, type-2 diabetes and cancers. Accordingly, dietary restriction (DR; either caloric restriction or intermittent fasting, with maintained vitamin and mineral intake) can extend lifespan and can increase disease resistance. Recent studies have shown that DR can have profound effects on brain function and vulnerability to injury and disease.
DR can protect neurons against degeneration in animal models of Alzheimer’s, Parkinson’s and Huntington’s diseases, and stroke. Moreover, DR can stimulate the production of new neurons from stem cells (neurogenesis) and can enhance synaptic plasticity, which may increase the ability of the brain to resist aging and restore function following injury. Interestingly, increasing the time interval between meals can have beneficial effects on the brain and overall health of mice that are independent of cumulative calorie intake.
The beneficial effects of DR (dietary restriction or calorie restriction), particularly those of intermittent fasting, appear to be the result of a cellular stress response that stimulates the production of proteins that enhance neuronal plasticity and resistance to oxidative and metabolic insults; they include neurotrophic factors such as brain-derived neurotrophic factor (BDNF), protein chaperones such as heat-shock proteins, and mitochondrial uncoupling proteins.
Some beneficial effects of DR can be achieved by administering hormones that suppress appetite (leptin and ciliary neurotrophic factor) or by supplementing the diet with 2-deoxy-d-glucose, which may act as a calorie restriction mimetic. The profound influences of the quantity and timing of food intake on neuronal function and vulnerability to disease have revealed novel molecular and cellular mechanisms whereby diet affects the nervous system, and are leading to novel preventative and therapeutic approaches for neurodegenerative disorders.
“It has been assumed that all of the benefits of DR feeding regimens are the result of a reduction in cumulative calorie intake (Weindruch and Sohal 1997), However, we have recently documented a clear dissociation between caloric intake and beneficial effects of DR in a study that compared the effects of periodic fasting (alternate day feeding) and limited daily feeding on various physiological parameters and neuronal vulnerability to excitotoxicity in C57BL/6 mice (Anson et al., ). We had noted that, in contrast to Sprague-Dawley rats which lose weight when maintained on a periodic fasting regimen, C57BL/6 mice did not lose weight. Measurement of food intake revealed that on the days they had access to food the C57BL/6 mice on the periodic fasting regimen consumed twice as much food as mice fed ad libitum.
…Remarkably, however, the mice on periodic fasting exhibited ‘anti-aging’ physiological changes equal to or greater than those maintained on the reduced calorie diet, including decreased plasma insulin and glucose levels, and reduced body temperature.
…Moreover, levels of the ketone body b-hydroxybutyrate were increased in the mice on the periodic fasting regimen, but not in the mice on the daily limited feeding regimen suggesting a change in cellular energy metabolism pathways (Anson et al., submitted). Periodic fasting was more effective than limited daily feeding in protecting hippocampal neurons against excitotoxic injury.
…These findings suggest that increasing the time interval between meals is beneficial, even when the size of the meals are increased to a level that results in no overall decrease in caloric intake.”
Rather than practice standard Intermittent Fasting, which often means eating a lot on one day and little or nothing the next, I simply understood and applied the biochemistry from this paper – and voila: I began to get extraordinary cognitive benefits from my CR regimen. The key was getting glucose and insulin low enough for long enough to stimulate ketones. We have made that easier than ever with the Daily Intermittent Fasting Meal Plan, available in the Getting Smarter Section to full members.
The Daily Intermittent Fasting Meal Plan is not a requirement for following the CR Way, but for people who want a better brain, it is certainly worth considering.