A new field is emerging that looks at meal timing and its influence on health. It’s called chrono-nutrition. The latest study in the field examined whether the timing of breakfast has an impact on human longevity.
The researchers found that, yes, the timing of breakfast does in fact influence your longevity. Here’s what you need to know to take advantage of this new science…
A study published last year found eating fruits with lunch, vegetables at dinner and a dairy snack in the evening reduced the risk of death from heart disease or from any cause.
The latest study looked at the relationship between the times we choose to eat breakfast and life expectancy. For those who prefer to tuck into their first fare later in the morning, the findings are not good news.
Earlier Breakfast Lowers Risk of Death By up to 12 Percent
Researchers examined data on breakfast times as part of two National Health and Nutrition Examination Surveys conducted in two periods covering 1988 to 1994 and 1999 to 2014. It included 34,609 Americans over the age of 40. During the follow up period, 10,303 people died.
The results, published in The Journal of Nutrition in January, show that eating breakfast between 6 AM and 7 AM reduces the likelihood of dying from heart disease, cancer, or any cause by six percent when compared to people who eat breakfast later, at 8 AM. This longevity advantage doubles to 12 percent when compared to those who wait until 10 AM to consume the first meal of the day.
While an observational study of this kind can’t determine why it’s detrimental to have a late breakfast, joint author Ashima Kant from City University New York said, “There is existing evidence that timing of eating may be linked to energy use and storage in the body.”
The Insulin Connection
The body’s natural biological cycles cause daily variations in many processes. These include body temperature, hormone secretion, and cardiovascular, digestive, and immune functions.
The timing of food intake plays a role in these processes and has been shown to affect weight control, blood pressure, cardiovascular risk factors and type-2 diabetes.
With aging, circadian rhythm disruption occurs, therefore meal timing – even the time we eat particular types of food – may also be relevant to how well we age.
“One of the possible explanations,” Dr. Kant speculated, “is due to a possible mismatch between when nutrients are consumed and the timing of release of the body’s metabolic machinery for using the nutrients.”
Eating later, the authors argue, disrupts the body’s “food clock” which is involved with the release of insulin and other hormones related to the digestion of food.
Since insulin lowers blood glucose, and insulin levels are at their highest early in the day, eating breakfast at that time is advantageous. Waiting until 10 AM means there’s less insulin to mop up the blood sugar. Chronically elevated blood sugar levels are linked to obesity, type-2 diabetes, and heart disease.
At least that’s the theory. In practice it may be those who prefer a later breakfast can disregard the findings of this study. Here’s why…
The science of chrono-nutrition is not only new, it’s exceedingly complex. Figuring out all the factors involved and how they interact will take years to unravel.
Although the authors of this study would have taken various factors into account, such as the quality of the diets and portion sizes, they provided no information on other influencing factors in their press release.
We know the time people ate their breakfasts but not whether it was eaten in daylight or artificial light. We also don’t know whether participants were carrying out aerobics or strength training in the morning, and if so, at what time. We have no information on sleep time or quality. These factors and more will influence the circadian body clock, and therefore the study results.
Professor Alexandra Johnstone, from the University of Aberdeen in Scotland, is a researcher in chrono-nutrition. She thinks we should focus our attention away from the mornings to another time of the day.
Eat Earlier in the Evening
“I think the weight of the evidence, so far, shows we should try and reduce evening intake. Have your last energy intake of the day, as early as possible. That is probably the clearest message that we have.
“Essentially, you process a meal much more efficiently in the morning than you do in the evening. So, if you eat a meal in the evening you tend to get higher concentrations of sugar and fat in the blood, and it takes longer for that to go back down to normal conditions.
“It’s not a huge leap to show if you are habitually having a lot of energy later in the day, you’re going to have a longer elevation of sugar and fat in your blood, therefore, this could contribute to your risk for diseases,” Professor Johnstone concludes.