There is a surprising amount of scientific research on meal patterns, meal frequency, and health. Several hundred studies have looked at meal frequency and while these studies often show mixed results, they also reflect some basic principles that you need to know about meals, meal timing, and your health.
A first principle might be summarized as "don't hold off and then gorge." Several studies have looked at the consequences of a 2-meal-per-day approach in which a person typically skips breakfast, has a large-sized meal at lunch, and then a second large-sized meal at dinner. As a general rule, this approach to meal timing has been shown to be problematic because it increases the risk of overeating as well as the risk of eating meals with less nutrient richness. When 2-meal-per-day plans have been compared with 3-meal-plus-3-snack plans, the plans with more frequent eating typically show improved health benefits. These health benefits include better insulin metabolism, better glucose metabolism, and better hunger control. Interestingly, plans with more frequent eating have also been associated with lower risk of atherosclerosis as measured by degree of thickness in the inner layers of the arterial walls.
A second important principle involves time of day. (Some researchers use the phrase "biological timing" in this context.) As a general rule, breakfast meals are associated with increased health benefits, especially if the breakfasts are nutrient-rich and portion controlled. Some studies have actually shown better glucose tolerance in the morning within several hours after waking. And at the other end of the day, repeated studies have shown problems with late-night dinners and late-night eating close to sleep. For example this type of late-night eating has been associated with increased risk of weight gain.
A third principle involves the need for quality control if you take a "grazing" approach. While the "hold off and gorge" approach to meal timing does not work, neither does a "grazing" approach unless it is portion controlled and high quality. By "grazing," researchers are referring to eating episodes that are more like snacks than meals. For example, if a person was awake from 7:00am to 11:00pm—16 hours—and ate 300 calories of food every two and one half hours from 7:00am to 7:30pm, that person would eat six times and consume 1,800 total calories. This "grazing" type of approach to eating can definitely work and provide health benefits, including better blood sugar control, better insulin metabolism, and better weight management. However—and this "however" is definitely important—this "grazing" type of approach can also backfire. Research studies show that the longer a person is awake and engaged in the eating process, the greater chance there is for overeating less healthy eating choices.
This type of problem has cropped up in the general U.S. adult approach to snacking. Over the past 30 years, snacking in the U.S. has greatly increased. It has been noted that 16% of U.S. adults currently get over 40% of their total daily calories from snacks, and half of all U.S. adults get at least 20% of their total daily calories from snacks. On average, adult snacks in the U.S. provide 24% of total daily calories, but only 13% of total daily protein and less than 17% of the daily requirements for vitamin A, vitamin D, folate, iron, and zinc. In short, our way of snacking in the U.S. has not shown itself to be a "grazing" approach that has provided us with health benefits.
When snack times are predictable and planned, they are usually associated with better health outcomes than when they are unpredictable and unplanned. Some of these planning-related benefits are clearly associated with better portion control. At WHFoods, you'll find that most of the snacks that we recommend are portion controlled in a natural way—for example, a cup of yogurt or a medium piece of fruit.
The value of predictability and planning may also extend beyond snacks. For example, routine family meals are associated in some studies with better glucose and insulin metabolism, especially if those meals are balanced and nutrient-rich.
If you combine all three principles above, what you end up with is a recommendation for 4 to 6 eating times over the course of the waking day that includes a morning meal and 3 to 5 other eating times that help distribute the total day's calories in a reasonable way. Holding off until late evening for dinner is not an approach that is supported by the research, nor is unpredictable, unplanned snacking. At the same time, however, more frequent eating with reasonable portion control and food selections is linked with a variety of health benefits in comparison with larger, less frequent meals. Our Smart Way of Eating Plan can provide you with a great example of a 3-meal, 2-snack approach with outstanding nutrient richness and total daily calories in the 1800-1900 calorie range.
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