When we eat may be more important than what we eat, scientists are saying. Time-restricted eating, limiting the hours when we eat, may be the answer to the many controversial diets that just don’t work. Do you have a few extra pounds you’d like to shed? I do! Read on to learn about the IF diet, a way of eating that doesn’t require counting calories or eliminating food groups, and has health benefits beyond just maintaining a healthy weight.
In lab animals, less energy intake results in increased life span. This has long been known by scientists. Energy intake can be lowered by eating less at each meal or by intermittent fasting, in other words, eating less frequently. It turns out that this good for your brain too.
Certain religions include fasting regimens in their traditions, and many famous historical figures, such as Plato and Ghandi, fasted regularly. Plato claimed that going hungry improved his ability to think. A quote from 3800 BC written on the wall of an Egyptian pyramid says, “Humans live on ¼ of what they eat; their doctors live on the other ¾.” It seems unlikely that humans throughout history ate and snacked throughout the day as most of us do.
Time-restricted eating
Intermittent fasting (IF), also called time-restricted eating, involves withholding food for a period, then eating normally. Effective fasting can last from as little as 14 hours a day, to one or two days a week, to one week a month. All regimens show benefits to health.
Firstly, intermittent fasting helps to control weight. That makes sense as you are likely cutting out snacking that you might normally have done during those hours. Excess weight is a risk for age-related cognitive impairment (possibly including Alzheimer’s disease) as well as cardiovascular disease, diabetes, certain cancers, and more. Many find intermittent fasting to be more effective in controlling weight than many other diets.
Secondly, fasting helps improve brain function. Nerve cells are more active when you’re hungry. Brain cells are challenged by the restriction in calories and react to become more efficient and form protective mechanisms. Fasting stimulates the production of proteins that promote growth and strengthen connections of brain cells. These proteins are called neurotrophic factors. An important one is BDNF (Brain Derived Neurotrophic Factor). Cognitive challenges (like puzzles or learning a new language), and exercise also increase production of these same proteins.
When you exceed 12 hours without ingesting any food, sugar levels become depleted and your body turns to using fat for energy. Ketones are produced when fat is burned for fuel and ketones are good for the brain. For example, a ketogenic diet is used to treat some forms of epilepsy, as ketones suppress seizures.
The BDNF protein increases the numbers of mitochondria (our cells’ energy factories) in the brain. This provides more energy for brain cells, an increased ability to form and maintain connections in the brain (which improves memory and ability to think), and an increased ability to repair damage to the DNA of cells, preventing cell aging.
So, scientists say 3 meals a day plus snacks is not the healthiest eating pattern. Mark Mattson, PhD at the National Institute on Aging at NIH, suggested that the statement: “Breakfast is the most important meal of the day” is not true and may have been a marketing ploy to sell breakfast foods! He has done extensive research into the pros and cons of intermittent fasting and published the results in the Journal of the American Medical Society (JAMA). Here is his list of benefits of intermittent fasting on the body and the brain:
· Blood—decreased insulin, insulin-like growth factor-1 (IGF-1), and leptin; increased ketones, adiponectin and ghrelin (hunger hormones that control appetite and energy balance)
· Liver—increased insulin sensitivity and ketone production; decreased IGF-1
· Intestines—decreased energy uptake, reduced inflammation, reduced cell proliferation
· Brain—improved cognitive function, increased neurotrophic factors, increased stress resistance, reduced inflammation
· Heart—decreased resting heart rate, decreased blood pressure, increased stress resistance
· Fat cells—lipolysis (fat breakdown), decreased leptin, increased adiponectin, decreased inflammation
· Muscle—increased insulin sensitivity, increased efficiency, decreased inflammation
Intermittent fasting promotes fat burning and the production of beneficial ketones. As well, the “housecleaning” system in humans that cleans out dead cells and other toxic and inflammatory substances, called autophagy, only activates when the bowels are not absorbing nutrients. Avoiding food for at least 12 hours is necessary to activate this essential cleaning system.
A word of caution...
If you have any chronic health condition, are elderly or for children, be sure to discuss this diet with your doctor before trying it. It is also recommended to begin slowly, for example, starting with 12 or 13 hours a day and increasing the time without food by one hour at a time to allow your body to adjust. Water, and black coffee or tea are allowed during periods of fasting and it is recommended to stay well hydrated.
Considering the potential health benefits of restricting calorie intake, I plan to shift my breakfast to a noon brunch and make sure I have my supper by 8pm, keeping my meals and snacks to an 8-hour slot each day. This seems to me to be the easiest way to take advantage of the many health benefits of intermittent fasting found by scientists. But some people may prefer to gain the same benefits by eating normally for 5 to 6 days a week and fasting (up to 500 calories per day) on the remaining days. This is sometimes referred to as the “5:2 diet” but, to me, this sounds like it would be much more difficult to adapt to.
With the intermittent diet, it’s not necessary to count calories or restrict any particular type of food, such as fats or carbohydrates. However, it’s always recommended to eat foods in their whole natural state and avoid highly processed foods as much as possible. And, again, talk to your doctor if you have any health concerns. This includes hard-to-control diabetes, children or adolescents, those over 70, pregnancy, chronic heart or kidney disease, low body mass (BMI), frailty or recent hospitalization, or history of an eating disorder.
If you are interested in learning more about the IF (Intermittent Fasting) diet, here are some sources of information:
Intermittent fasting can help ease metabolic syndrome—Medical News Today
Why fasting bolsters brain power—Mark Mattison at TEDx John’s Hopkins University (about health benefits)
Intermittent fasting: Transformational technique---Cynthia Thurlow TEDx (about weight loss)
Impact of Intermittent Fasting on Health and Disease Processes---M.Mattson, US National Library of Medicine
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