Ten years ago, a study was published in the New England Journal of Medicine (J.A. Jenkins et al. "Nibbling versus Gorging: Metabolic Advantages of Increased Meal Frequency." 1989, 321, 14:929-934). It reported that frequent meals may be better for you than the same calories, protein, fat and carbohydrate ratio and content, but swallowed in just three square meals during the day. It was good not only for weight loss, but for blood cholesterol: it levels plummeted 15 percent. Cortisol fell more than 17 percent. An important reminder: cortisol is, besides its stress-relatedquality, a fat-forming hormone.

Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD 21224, USA.

Intermittent fasting (IF; reduced meal frequency) and caloric restriction (CR) extend lifespan and increase resistance to age-related diseases in rodents and monkeys and improve the health of overweight humans. Both IF and CR enhance cardiovascular and brain functions and improve several risk factors for coronary artery disease and stroke including a reduction in blood pressure and increased insulin sensitivity. Cardiovascular stress adaptation is improved and heart rate variability is increased in rodents maintained on an IF or a CR diet. Moreover, rodents maintained on an IF regimen exhibit increased resistance of heart and brain cells to ischemic injury in experimental models of myocardial infarction and stroke. The beneficial effects of IF and CR result from at least two mechanisms--reduced oxidative damage and increased cellular stress resistance. Recent findings suggest that some of the beneficial effects of IF on both the cardiovascular system and the brain are mediated by brain-derived neurotrophic factor signaling in the brain. Interestingly, cellular and molecular effects of IF and CR on the cardiovascular system and the brain are similar to those of regular physical exercise, suggesting shared mechanisms.  A better understanding of the cellular and molecular mechanisms by which IF and CR affect the blood vessels and heart and brain cells will likely lead to novel preventative and therapeutic strategies for extending health span.

Ever thought what makes you start and finish eating? Right, hunger makes you start and feeling full makes you stop. But how about breakfast? They say it's the most important part of your meal plan and you eat it just for the sake of it. How about snacking, should you have snacks? How often? Don't we take for granted that skipping breakfasts and having two square meals a day is bad for you? Bad for what exactly? Let's see if there's any rationale behind.

Studies have demonstrated that a good breakfast is usually associated with an improvement in mental tasks performance later in the morning, while lunch does exactly the opposite, plus it has rather negative effects on mood. Late in the afternoon, meals appear to have a positive effect on tasks involving sustained attention or memory. (British Journal of Nutrition. 77 Suppl 1:S105-18, 1997)

Recently, researchers in Johannesburg, South Africa, reported that frequent meals reduced appetite by 27%! This is how they figured it out. One group of healthy overweight men had a big breakfast, then next meal only after 5 hours when they had nothing to eat. Another group ate the same amount of same food but divided in 5 hourly meals. Guess who ate more when after these 5 hours they had an "all you can eat" meal? Yes, the gorgers did. What's more, compared to them, the nibblers had much more favorable insulin and blood glucose profiles. (International Journal of Obesity & Related Metabolic Disorders. 23(11):1151-9, 1999).

These favorable blood readings can explain the fact that more frequent meals can be protective against cardiovascular diseases. For example, in the Department of Vascular Surgery, Charing Cross Hospital, London, doctors investigated how habitual meal frequency influenced atherosclerosis. After they made the necessary adjustment for 120 patients' age, sex, smoking, diabetes, blood pressure, and body mass index, the odds for peripheral arterial disease among those eating between meals (grazing) compared with those who did not, was 1:2. (Journal of Cardiovascular Risk. 6(1):19-22, 1999)

Now, how about weight loss? Scandinavian researchers reported that competitive boxers who tried to lose weight by reducing their calorie intake, lost same amount of body weight, but it was mostly lean body mass loss in those who had their ration in two square meals compared with those who had 6 meals a day. (Scandinavian Journal of Medicine & Science in Sports. 6(5):265-72, 1996)

To tell you the truth, while dieticians and nutritionists seem to adopt the "nibbling versus gorging" model of daily meal planning, not all doctors agree with it. Many diet reviewers concluded that there's no sufficient long term studies proving the benefits of "nibbling". For example, Nutrition Research Group, University of Surrey, UK, did not confirm that nibbling is beneficial in reducing the concentrations of lipid and hormones on the long run. (European Journal of Clinical Nutrition. 50(8):491-7, 1996).

There can more to this if we look into cancer risks studies. There are many clinical reports about higher risk of many cancers of stomach and intestines in people who are used to eat more meals during the day for many years. For example, a higher daily meal frequency was responsible for 13% of 3350 cases of colorectal cancer in Northern Italy, as reported by National Tumor Institute, Milan, Italy.

It is interesting, that intake of more than two cups of coffee a day had a protective effect against cancer (Nutrition & Cancer. 30(3):182-5, 1998) thus providing a simple measure to counterpart the negative effect while keeping the possible benefits of frequent meals.