A calorie is not a calorie. It’s not just about what you eat, but when you eat.
Mice are nocturnal creatures. They eat during the night and sleep during the day. However, if only feed Mice during the day gain more weight than if they were fed a similar amount of calories at night. Same food and about the same amount of food, but different weight results, as you can see in the graph below and at 0:18 of my video. Eat more calories in the morning to lose weight, suggesting that eating at the “wrong” time can lead to disproportionate weight gain. In humans, the wrong time would presumably mean eating at night.
Recommendations for weight control often include Advice to limit eating during the night, but this was largely anecdotal until it was first studied experimentally in 2013. Researchers instructed a group of young men not to eat after 7:00 pm during two weeks. Compared to a control period during which they continued their usual habits, they ended up weighing about two pounds less after the nighttime eating restriction. This is not surprising, given that dietary records show that study participants inadvertently ate fewer calories during that time. To see if time has metabolic effects beyond limiting eating opportunities, people would have to be forced to eat the same amount of the same food, but at different times of the day. the us army floor We are eager to carry out such an investigation.
In their first series of experiments, Army researchers had People eat only one meal a day, either breakfast or dinner. The results clearly showed that the breakfast group lost more weight, as you can see in the graph below and at 1:35 in my video. When study participants ate Just once a day for dinner, their weight didn’t change much, but when they ate once a day for breakfast, they lost about two pounds per week.
As in the nighttime eating restriction study, this is to be expected, given that people tend to be hungrier at night. Think about it. If you went nine hours without eating during the day, you would be hungry, but people go nine hours without eating during the night all the time and don’t wake up hungry. There is a natural circadian rhythm of hunger that peaks around 8:00 pm and drops to its lowest level around 8:00 am, as you can see in the graph below and at 2:09 in my video. Perhaps that’s why breakfast is usually the smallest meal of the day.
The circadian rhythm of our appetite is not only behavioral, but also biological. It’s not just that we are hungrier at night because we have been running all day. If you stayed up all night and slept all day, you would be even hungrier when you woke up that night. To untangle the factors, scientists used what is called a “forced desynchrony” protocol. Study participants stayed in a windowless room with dim, constant light, and slept in staggered 20-hour cycles so they could fully wake up. This continued for more than a week, so the subjects ended up eating and sleeping at different times throughout all phases of the day. Researchers could then see if the cyclical phenomena are actually based on internal clocks or are simply a consequence of what you’re doing at the time.
For example, there is a daily change in our core body temperature, blood pressure, hormone production, digestion, immune activity, and just about everything else, but let’s use temperature as an example. As you can see in the graph below and at 3:21 in my videoour body temperature generally money around 4:00 a.m., dropping from 98.6°F (37°C) to more like 97.6°F (36.4°C). Is this just because our body cools down while we sleep? No. By keeping people awake and busy for 24 hours straight, it can be experimentally shown that this happens at about the same time no matter what. It is part of our circadian rhythm, just like our appetite. It makes sense then, if you’re just eating one meal a day and you want to lose weight, you’ll want to eat in the morning, when your hunger hormones are at their lowest. 
It sounds reasonable, but it’s starting to get strange.
Army scientists repeated experiment, but this time, they had the participants eat exactly 2,000 calories, either for breakfast or dinner, suppressing their appetite. The subjects were also not allowed to exercise. Same amount of calories, so same weight change, right? No. As you can see in the graph below and at 4:18 in my video, the breakfast-only group still lost about two pounds per week compared to the dinner-only group. Two pounds of weight loss eating the same amount of calories. That is why this concept of chronobiology, meal timing (when to eat), is so important.
Isn’t that wild? Two pounds of weight loss per week while eating the same amount of calories! However, that was a pretty extreme study. What if we simply shifted a higher percentage of calories to the first few hours of the day? That’s the topic of my next video: Eat breakfast like a king, lunch like a prince, dinner like a beggar. First, let’s take a break from chronobiology to look at the Benefits of garlic to fight cancer and the common cold. Then we will continue reviewing other videos in the related posts below.
If you missed the first three videos in this extended series, also check out the related posts below.
