How many of us can honestly say that we've never raided the fridge at 3 a.m., egged on by an uncontrollable hunger for ice-cream? Doing this once or twice is fine, but new research says that if you make this a habit, you could be in trouble.
High blood fat levels are associated with both heart disease and diabetes. These diseases are associated with a lifestyle where humans ignore the signals of the biological clock, and eat in the evening and night.
Eating late at night increases the risk of heart disease and diabetes by raising levels of harmful blood fats, warns new research.
Shift work, in particular, is triggering the killer illnesses by leading to people eating their meals at the wrong time of day, according to the study from the National Autonomous University of Mexico.
Th elate-night snacking is a strange habit, and there are various theories as to why so many of us are inclined to raid our cupboards and fridges past our bedtime. A previous study has suggested that our craving for certain types of food — those rich in starch, salt, and sugars — late in the evening may be explained by our ancestors' needs.
Main author of the study explained that early humans did not know when and where their next meal would come from, so binge eating late in the day where possible allowed their bodies to store the energy needed for survival.
But now, our snacks are driven more by pleasure than by necessity, so their effects are much less wholesome. Researchers agree that caving in to your munchies and eating late in the evening leads to negative health outcomes, such as a heightened risk of obesity.
Again,this may not only be tied to the snacks' nutritional value, though; it might also be linked to how our bodies are programmed to work, and how our circadian or internal clocks function. Our bodies are adjusted to the natural day-night cycle, and so they tell us when we should eat, sleep, and be active.
Moreover,if the circadian clock is ignored, health and well-being are also impacted. For instance, it was found that eating outside the normal waking and activity hours may cause excess weight gain.
And now, emerging research from the National Autonomous University of Mexico in Mexico City suggests that late-night eaters may also be predisposed to diabetes and heart disease.
The new research, which was led by Prof. Ruud Buijs, suggested that"upturning" eating habits dictated by our biological clocks can lead to heightened blood fat, or triglyceride, levels. This, in turn, is linked to metabolic and heart diseases.
The new findings of the latest research work were published in the popular journal Experimental Physiology.
We should stop 'eating at times when we should sleep'
In this study Prof. Buijs and team led a series of experiments in rats, focusing on blood triglyceride levels and the impact of the circadian clock on their fluctuation.
While following their tests, the scientist team noted that when fed at the beginning of their normal rest interval, the animals displayed substantially higher triglyceride levels.
But if fed at the start of the period when their bodies were normally fully active, however, the rats did not experience the same sharp increase in blood fats.
Furthermore, following these experiments, the researchers chose to remove the part of the animals' brains that is largely responsible for regulating circadian rhythm, so that they could see whether that would impact the results.
Generally, in the brains of humans and other mammals, the suprachiasmatic nucleus (SCN)is tasked with keeping body clocks up and running and in sync with each other.
After the scientists removed the SCN from the rats' brains, they noticed that no matter when the animals were fed, their triglyceride levels no longer fluctuated.
Thus, the researchers concluded that if we"mess" with our normal circadian rhythm on a regular basis — for instance, by eating late at night — the way in which our bodies respond could be affected. In the case of heightened triglyceride levels, it might give rise to diabetes and cardiovascular disease.
Prof. Buijs and colleagues warn that these dangerous inverted patterns are now fairly common "in westernized countries (where late-night dinners are habitual)and in night workers." So, night owls, beware: it's best to eat early, and not to cave in to the midnight munchies.
"The fact that we can ignore our biological clock," adds Prof. Buijs, "is-important for survival; we can decide to sleep during the day when we are extremely tired or we run away from danger at night."
"However, doing this frequently — with shift work, jet lag, or staying up late at night — will harm our health in the long-term especially when we eat at times when we should sleep.
When should we eat our meals?
The best times to eat meals are the regular ones. Nutritionist Dr Kristin Eckel Mahan says that the best eating schedule is one in sync with circadian rhythms and your 'activity levels.'
She says that our bodies are most 'sensitive' to insulin - which helps us break down glucose - earlier in our day. We don't really get an uptick later on, our insulin sensitivity 'wanes as the day progresses.'
'Somebody that has a late chronotype' - tending to stay up late and get up late- 'is going to be shifted a few hours later than someone who gets up early,' Dr Eckel Mahan says.
But, whenever you getup, do eat breakfast, research says. People who at a big breakfast had 33percent lower blood triglyceride levels than people who at a big dinner,according to a 2013 study.
Circadian rhythms influence our metabolism and hunger, and eating influences our circadian rhythms. Another study showed that our bodies are able to process or 'burn' more calories at 8am than they are at 8pm. This puts people who do nigh tor rotating shift work at a distinct metabolic disadvantage.
But, Dr. Eckel Mahan says, people doing night or shift work should still eat in the active phase of their day, rather than the light one.
'The brain clock should be sort of in sync with the light-dark cycle,' and our activity and eating schedule should be in sync with the two, she says.
But for people who can't have it all, better to follow the activity phase than the light clock.'It's the idea of alignment: eat in your active phase, not your resting phase,'says Dr Eckel Mahan.
Key findings from the study
- The body is less able to process triglycerides when we eat at the wrong time, the study found
- Triglyceride build-up in the blood increases our risk of developing heart disease and diabetes
- The researchers found that when they took out the part of the brains of rats that regulates the biological clock, when they ate made no difference to triglyceride buildup in their bloodstreams
- Night and rotating-shift workers are particularly at risk because their eating schedules are inevitably out of sync with their biological clocks