Body fat and your chart’s “Area Under the Curve”

With fasting or eating, every minute counts. And there’s a scientific reason for that.

Jason Fung, a physician specialising in kidney disease (and thus obesity and diebetes), pointed to a research study. I’ve read his article, but not the paper. As a lay person, this was my understanding of it: basically there were two groups of people who ate the same amount of food. What differed was the time of day they ate that food. The people who ate the big meal closer to breakfast time lost significantly more weight.

How could that be? Well, your body responds to food differently at different times of the day (why is that, I haven’t gotten that far in my understanding, I’d be intrigued to learn more). One of the responses is your body’s response with insulin. Simplistically that hormone signals to your body’s systems “Hey lads, we’ve got glucose floating around in the blood from that food yer man just ate, so we need to shtart working a bit harder and store that away for later user” (for some reason, the systems speak with a County Clare accent).

Fung points out specifically that the study shows the total calculated Area Under the Curve for the study’s participants for their circulating insulin and a couple of other hormones throughout the day (Figure 3 in the paper).

In essence, you can total up the amount of insulin you had floating around in your body during the day, and it’s a good predictor for how much body fat you’ll lose, keep or store.

And, newsflash, you have control over how much insulin you have floating around in your body. You control that total Area Under the Curve in your daily “chart”, if you were to measure your body’s responses to food.

From what I’ve understood from Dr. Fung in his book The Obesity Code:

  • All foods eaten give some kind of insulin response in your body
  • Your body is either in fat storage mode or fat burning mode, there is no middle-mode
  • What you eat will have different insulin responses (eating bread or other highly refined grain will have an effect on your insulin close to eating pure glucose; compare that to some fibrous veg, and fats, that gives a lower insulin response)
  • When you eat also affects your body’s insulin responses (eat throughout the day, and your body will be in fat-storage mode all day, see Milky Tea: A trojan horse to Irish Obesity?)
  • The quickest way to drop your body’s insulin levels is to not eat
  • Not eating all day is absolutely normal. Ancient human traditions made a point of not eating (and today we’d imagine they were already “starved”). By the way, in the Irish language, the word for Wednesday (Dé Céadaoin) means “the first fast” and the word for Friday (Dé hAoine) means “the fast”.
  • Obesity has a huge time component. Are you getting fat “with age”? It could be that your body has had a total “Area Under the Curve” of insulin over your lifetime that’s higher than your body has been “built” for. Basically, if your eating habits over decades has brought your average insulin levels up, eventually you feel like you’re starting to “get fat with age”.
  • Chronically high insulin levels means your body’s systems have to ignore that messaging hormone (like the story of the boy who cried wolf). This is what they call “insulin resistance”. Your body then has to produce even more insulin to get your fat storage mechanisms to really take it seriously, so that you don’t have continually dangerous levels of glucose in your blood. So if you’re a little fat already, you’re probably almost predictably going to get fatter.
  • Lowering insulin for the long-term also has a huge time component. If you’ve been fat (I’ll say fat, because “obese” is a way for us to hide behind a label) for many years, you’ll have to work much harder at it that someone who has only had a harmful mix or hormones the past month.

In conclusion, you have control over a huge factor in your body’s composition.

I don’t think Fung addresses the psychological aspects of eating extensively enough. My drive to eat absolutely increases in times of daily stress. It’s all very well to talk logically about insulin levels, but how do you deal with an afternoon that’s really dragging, if you can’t have that milky tea you’re used to? At least he touches on the subject with reducing stress levels with meditation, but I think the drivers of the mind are much stronger than he seems to accept.

Study reference:

Jakubowicz et al, “High Caloric Intake at Breakfast vs. Dinner DifferentiallyInfluences Weight Loss of Overweight and Obese Women”, in Obesity 21 (12), December 2013.