Meal Skipping: Good or Bad?

Many people find that the Shangri-La diet makes it easy to skip meals. It is natural to ask: How does meal skipping affect overall health? Having eaten one meal per day for the last six years, let’s just say I care about the answer.

For more than half a century it has been clear that calorie restriction is a powerful way to increase the lifespan of rats and at least a few other species. An experiment with monkeys seems to be headed for the same result: calorie restriction increases lifespan.

Calorie restriction is a complex treatment. Calorie-restricted rats eat less, they lose weight, they may eat less often, they eat less protein, they eat less carbohydrate, and so on. Which of these changes cause the health benefits? A researcher at the National Institute of Aging named Mark Mattson has been asking this question. He and his co-workers have discovered that the benefits of calorie restriction can be achieved by eating less frequently, even when there is little or no weight loss. The implication is that skipping meals, if anything, is likely to be beneficial.

One study, published in 2003, compared four groups of mice. One group (ad lib) got all the food they wanted every day. Another group (calorie restriction) got 60% of the amount of food that the first group got. A third group (intermittent fed) got all the food it wanted but only every other day. A fourth group got the same overall amount of food as the intermittent-fed group, but without a one-day “fast” between feedings. After 20 weeks, the calorie-restriction mice weighed about half what the ad-lib mice weighed; the other two groups weighed about 90% of what the ad-lib mice weighed. The most interesting measure was what happened when kainic acid (which kills neurons) was injected into the brains of the mice. The measure was how many neurons survive. The results were not easy to completely sum up but they did show that intermittent feeding was more protective than ad lib feeding, and at least as protective as calorie restriction. In other research from Mattson’s lab, intermittent feeding has been found to be healthier than ad lib feeding in other ways — for example, a rat study found protection against heart-attack damage. A review article by Mattson concluded that “both caloric (energy) restriction (CR) and reduced meal frequency/intermittent fasting can suppress the development of various diseases and can increase life span in rodents.”

What about humans? In January I was contacted by Dr. James Johnson, Dr. Donald Laub, and Sujit John, who had been studying the effect of intermittent feeding on humans — starting with themselves. Johnson had tried to lose weight via an on-day-off-day diet: One day you eat normally, the next you eat 20% of what you would usually eat. I think he based this diet on Mattson’s results. Eating only every other day — the usual regime in Mattson’s experiments — was just too hard but Johnson found that eating a percentage on the order of 20-30% of usual intake on the off days was just bearable and did produce weight loss. Johnson found that not only did it produce weight loss, it had many other beneficial effects, such as an improvement in asthma symptoms. He first noticed these improvements when he tried the diet himself (he wanted to lose weight); later he saw similar improvements when his friends did the diet, the same path I followed with SLD. Johnson, Laub, and John have just published an article in Medical Hypotheses about their ideas. They were interested in my weight-loss ideas as a way of making the on-and-off regime more bearable — to reduce the hunger involved. “The oil and sugar water seem to work well,” Dr. Laub wrote me recently.

Here is the abstract of their Medical Hypotheses paper:

Restricting caloric intake to 60-70% of normal adult weight maintenance requirement prolongs lifespan 30-50% and confers near perfect health across a broad range of species. Every other day feeding produces similar effects in rodents, and profound beneficial physiologic changes have been demonstrated in the absence of weight loss in ob/ob mice. Since May 2003 we have experimented with alternate day calorie restriction, one day consuming 20-50% of estimated daily caloric requirement and the next day ad lib eating, and have observed health benefits starting in as little as 2 weeks, including insulin resistance, asthma, seasonal allergies, infectious diseases of viral, bacterial and fungal origin (viral URI, recurrent bacterial tonsillitis, chronic sinusitis, periodontal disease), autoimmune disorder (rheumatoid arthritis), osteoarthritis, symptoms due to CNS inflammatory lesions (Tourette’s, Meniere’s) cardiac arrhythmias (PVCs, atrial fibrillation), menopause related hot flashes. We hypothesize that other many conditions would be delayed, prevented or improved, including Alzheimer’s, Parkinson’s, multiple sclerosis, brain injury due to thrombotic stroke atherosclerosis, NIDDM, congestive heart failure.
Our hypothesis is supported by an article from 1957 in the Spanish medical literature which due to a translation error has been construed by several authors to be the only existing example of calorie restriction with good nutrition. We contend for reasons cited that there was no reduction in calories overall, but that the subjects were eating, on alternate days, either 900 calories or 2300 calories, averaging 1600, and that body weight was maintained. Thus they consumed either 56% or 144% of daily caloric requirement. The subjects were in a residence for old people, and all were in perfect health and over 65. Over three years, there were 6 deaths among 60 study subjects and 13 deaths among 60 ad lib-fed controls, non-significant difference. Study subjects were in hospital 123 days, controls 219, highly significant difference. We believe widespread use of this pattern of eating could impact influenza epidemics and other communicable diseases by improving resistance to infection. In addition to the health effects, this pattern of eating has proven to be a good method of weight control, and we are continuing to study the process in conjunction with the NIH.

Huh. My question is: Am I skipping enough meals?