Looks Like When We Eat Is Just as Important as What We Eat5 years ago | Nutrition
By Joy Stephenson-Laws, JD, Founder
There is an old adage that you should follow: “Eat breakfast like a king, lunch like a prince, and dinner like a pauper.”
Unlike many other wives’ tales about health that have been proven over the years to be wrong, (like drinking a cold drink can give you a sore throat or a cold), credible research continues to support the idea that having our largest meal earlier in the day followed by smaller ones later on offers a variety of health benefits.
If you think this approach sounds similar to intermittent fasting (also known as IF), or other eating regimens that include fasting in one form or another, you wouldn’t be too far off the mark. But rather than arbitrarily pick certain days and times to restrict food intake, this approach aims to better align eating patterns with circadian rhythms. These are the 24-hour cycles that govern literally all our bodily functions from when we get up and go to sleep, when our metabolism is most active and when various organ systems work at their peak efficiency.
It turns out that these circadian rhythms are far more complex, and have a far greater impact on our health, than previously thought. To understand why this is, it’s important to keep in mind that each of us has a general “master clock” for our bodies that governs our sleep-wake cycles in response to light exposure.
From an evolutionary standpoint, this makes total sense. Before artificial light, our ancestors hunted, gathered and ate during daylight hours and slept during the night hours. The “holdover” from this adaptive mechanism still rules our bodies to this day. But researchers also have known for a while that our various organ systems (and even our cells) have their own clocks – call them sub-clocks – which in turn govern their functioning and activity cycles. So, in reality, each of us has a collection of “clocks” controlling everything in our body.
One researcher explained that our bodies need to get so much done in a 24-hour period that the only way to do this is to do different tasks at different times of the day. We can help our bodies do these various jobs better if we work to align our daily activities – and especially eating – with our bodies’ natural rhythms. These include sleeping when our body clock wants us to sleep (when the sun goes down), exercising when our bodies are at their peak muscular and cardiovascular performance (early evening) and, most importantly, for our metabolic health, eating when our digestive and related systems are primed and expecting food (earlier in the day).
Early Time-Restricted Feeding Better Aligns with Biological Clocks
In comparison to IF, timing your food intake to better match your personal circadian rhythms is known as “early time-restricted feeding,” or ETRF for short. Similar to IF, which often recommends having 16 hours without eating and 8 hours with eating, ETRF also advocates limiting your food intake to an 8-10-hour daytime window. This window may begin at different times in the morning depending on your personal circadian rhythms.
The big difference, however, is that ETRF also usually recommends “front loading” the bulk of your nutrients and calories to the morning and midday hours. This is in stark contrast to the 15-plus hours that most people eat throughout the day which, proponents of ETRF say, puts us in constant conflict with our biological clocks. The result are problems with our metabolism, including an increased risk of obesity, diabetes, high blood pressure, some cancers and other weight-related health issues.
For example, our pancreas increases the amount of insulin – which controls blood sugar – it produces during the day and this production slows down dramatically during the night. This is probably why studies show that blood sugar control is best in the morning and at its worst in the evening. There is another clock that controls how many and when our guts produce digestive enzymes and when it is most efficient at absorbing nutrients. And, don’t forget the bacteria that live in our gut and play a key role not only in digestion but also in helping keep our immune systems at their peak. They, too, have their own clocks. Last, but not least, is that gastric emptying and gastrointestinal motility is highest in the morning.
Put it all together, and it becomes easy to see how disrupting these processes by eating when our bodies aren’t “programmed” to eat can wreak havoc on our health by making our bodies do something they aren’t supposed to be doing. Perhaps one of the biggest culprits here is snacking at night. When the sun sets, our brain is starting to release melatonin to help prepare us for sleep. By eating late at night, we’re telling our digestive system it’s still daytime while our brains are telling the rest of our body to go to sleep!
While more research needs to be done with the relationship between eating and circadian rhythms, in one recent study, genetically identical mice either had 24-hour access to high-fat, high-sugar foods or had just an 8-hour access to the same food in the same amounts.
Despite eating exactly the same food and ingesting the same number of calories, the 24-hour access mice became obese and showed signs of illness while those who only could eat eight hours a day did not. And keep in mind, they ate the same amounts of the same foods – the only difference was when they ate. In a similar study, mice fed when their bodies were primed for rest showed signs of diabetes, metabolic syndrome and even impaired cognitive function.
In another study, with humans this time, a small group of pre-diabetic men were first allowed to eat their meals over the course of twelve hours. In the second phase, this window was shortened to six hours.
The men on the ETRF regimen had lower insulin levels, reduced oxidative stress, less hunger and even lower blood pressure.
These results do not mean you should only eat in the morning and forget about eating the rest of the day. What it does mean, is that you probably should have dinner like the proverbial pauper rather than like the king or the prince.
In fact, one study from Israel suggested that people who were overweight lost more weight and had greater improvements in markers such as blood sugar, insulin and cardiac risk when they had a large breakfast followed by a moderate lunch and a small dinner when compared to a group did just the opposite by having a small breakfast and a large dinner. And it appears that you don’t need to make drastic changes to see positive results. In one group of obese individuals, reducing their eating “window” to 11 hours from 14 hours resulted in enhanced weight loss and improved sleep.
If, after talking with your healthcare provider, you decide to try ETRF or another fasting-based diet, you still need to be sure that your body is getting all the macro and micronutrients it needs and in the right amounts. It’s also important to make sure you are getting them from primarily plant-based foods that you prepare at home. This will help ensure they are in a form that is easiest for your body to metabolize and use.
Nutritional testing to see where you may have any imbalances is also important, but you and your doctor should keep in mind that research now shows that your circadian rhythms also impact nutrient absorption so you may want to consider doing them at different times of the day to get the most accurate results.
Enjoy your healthy life!
The pH professional health care team includes recognized experts from a variety of health care and related disciplines, including physicians, attorneys, nutritionists, nurses and certified fitness instructors. This team also includes the members of the pH Medical Advisory Board, which constantly monitors all pH programs, products and services. To learn more about the pH Medical Advisory Board, click here.