Breakfast? Intermittent fasting? Late-night snacking? Depending on what you read, all of these can be glorified or vilified. But now, the American Heart Association (AHA) has released a “scientific statement” on meal-timing and frequency, and how they affect weight and heart disease. (1) Below are some highlights of the 27-page document (Yes, I downloaded the whole thing and dug). But keep in mind that even the AHA is limited to translating the current research available, and more is sure to come.
- Breakfast: Yes. We are 31% less likely to be obese if we are breakfast eaters. Diabetes is also much more prevalent in non-breakfast eaters.
- “Breakfast”: Typically eaten before 10 am
- Consumed within 2 hours of waking
- Comprised of 20%-35% of total daily calories
- Meal Frequency: Meh. Not so much supportive data on eating several small meals. It works for some, but also sets some up to over-indulge on calories. Two smaller studies have shown a benefit to this practice, though. So see what best suits your lifestyle and personality.
- Intermittent Fasting: What even is intermittent fasting? Here are the two primary types.
- Alternate-day fasting involves a “fast day,” when individuals consume ≤25% calories in a 24-hour period, alternated with a “feast day,” when unlimited food consumption is permitted for 24 hours.
- Periodic fasting requires participants to fast only 1 or 2 days per week and allows 5 to 6 days of unlimited food consumption per week.
The initial information on this is positive, but I am very skeptical for a few reasons:
- There are not yet any long-term studies evaluating the success or health of intermittent fasting.
- Many personalities do not do well with unlimited anything, and may over-indulge beyond healthy boundaries on “feast days”.
- We don’t know how this back-and-forth pattern will affect the body’s natural hunger cues and rhythms.
- Nighttime Eating: There have been several large-scale studies that indicate an increase in metabolic syndrome, obesity, and chronic inflammation with late-day eating. One study had subjects simply move 300 calories (of chocolate ice cream, no less) from dinner to breakfast, and they lost an average of 45 pounds in 36 weeks!
- Narrow Daytime Eating Windows: Technically a type of intermittent fasting, this is a relatively new idea, with little research thus far. However, restricting the number of hours in the day that a person eats has shown promise in some small mouse studies. (2)
- Mice were on high-fat, high-sugar diets
- One group was permitted to eat any time they wished
- The other group was only permitted to eat within an 8-hour window.
- The mice were eating the same number of calories
- The ones who ate only for 8 hours did not become as obese as the 24-hour group.
- Less than 12% of their body weight was fat, as opposed to 40% for the any-timers.
- However, once they had access to the same food any time they wanted, the mice’s weight gain doubled even though the calorie-intake was the same.
Can eating within an 8-hour window and fasting for 12-16 hours improve our health? It sounds difficult to me, but once a habit/lifestyle has been adopted, it is much easier to follow. First and foremost, CHECK with your personal physician before embarking on any new eating plan. And if you try any of these ideas, shoot me an email and let me know how it worked for you.
(2) Cell Metabolism; 2009