I'm asking this sincerely, but don't people from traditionally healthy Asian countries eat a hell of a lot of rice? That's my first thought every time someone mentions how bad carbs are. But I have trouble finding any non-antecdotal data.
I want to believe the obesity problem is more of a portion control thing, for example, when McDonald's opened, did a normal adult actually eat a hamburger and small fries for lunch instead of a big mac and large fries? But once again, I always have trouble finding any real data to verify my hypothesis.
The problem is that when the "low fat" fad started, a lot of the the fat in processed food was replaced by sugar. Read ingredient labels... there's sugar or corn syrup in almost ALL low-fat/fat-free foods. So not only were you not getting the fat that would have worked to satiate your appetite, you were getting sugar on top of the carbs.
I don't have any hard data for you but I believe you're right about the portion control.
Junk food is also popular in Japan, though probably not as much as in the US. However, in general portions are smaller here in Japan and people don't drink soft drinks all day. Apparently the average American geek needs as much food as a Japanese construction worker.
"According to the latest health ministry figures, however, 29% of Japanese men aged 20 to 60 are overweight - an increase of 5% in only five years and a long way off its 2010 target of below 15%"
That article tends to re-enforce my line of thinking, that Surgeon General's advice of less-fat, more-carbs, and more exercise isn't cargo cult science.
Some of the conclusions from that article:
+ [H]ealth experts have warned that dietary changes, coupled with an increasingly sedentary lifestyle, are storing up trouble for Japanese children who, in their taste for burgers and instant noodles, have more in common with the average western teenager than with their tofu-loving grandparents.
+ "The Japanese used to eat food high in protein, but over the past few decades there has been a shift towards eating more animal fat, and that is at the root of the problem," said Shinobu Matsui.
+ [The Health Japan 21 program] has drawn up nutrition charts aimed at those most at risk of obesity - men, children and people living alone - encouraging them to eat more rice and vegetables and to cut down on meat.
National Geographic did a piece some time ago about the average servings at McDonald's and other fast-foods 40 years ago compared to now, but I can't find it, and I fail to Google it (if it is available online, that is).
I can tell you, the portions were significantly smaller in all cases.
Genetics plays a part. Diabetes in Asians is a different disease; the excess fat in Asian men is stored in the muscles rather than around the belly. 150 generations of eating rice will change things. By comparison, food like potato (now a stable) have only been around in northern Europe for 6-8 generations.
The rice portion is significantly smaller (about as big as your asian hands could carry if they shaped as a bowl) than the typical north american starch portion.
This is an appealing take but ultimately oversimplified. Calories in equals calories out, this is self evident. Assuming that calories in has no effect on calories out or vice versa is where you make the mistake - they are dependent variables and quite obviously so. Don't eat much and you get cold and lethargic, go work out and you work up an appetite.
Saying you're fat because you eat too much is like saying you're an alcoholic because you drink too much. It's true but it doesn't say anything about how to solve the problem and it mixes up cause and effect - in the former case you're eating more because you're getting fat (due to insulin resistance, caused by chronically high consumption of carbohydrates according to some or due to chronically high consumption of fructose according to others) and in the latter case you're drinking more because you're dependent upon alcohol.
"Saying you're fat because you eat too much is like saying you're an alcoholic because you drink too much. It's true but it doesn't say anything about how to solve the problem and it mixes up cause and effect"
I think you're really close to getting at the root of this problem right here. Fundamentally, we're talking about a behavioral compulsion here - people are literally getting addicted to food. Fructose is the substance that's hijacking the brain's reward system. A particular individual's susceptibility to obesity is very likely set up by the same factors that function in other addictions, whether chemical (as in alcoholism) or behavioral (as in gambling) - namely, dysfunctional family systems, psychological trauma, stress, etc. If this is, in fact, what's really going on then the solution is to (A) treat obesity as an addiction and (B) limit the proliferation of fructose in the food supply.
It's more complex than just calories in - calories out. Just to complete your simple equation, what you're saying is:
calories in - calories out = fat stored/burned.
So for calories in == calories out, stable weight.
For calories in > calories out, weight gain.
For calories in < calories out, weight loss.
The mistake that most people make is that they assume that the left side is independent of the right side. We can rewrite the equation as:
//Assume that a negative fat stored is fat burned
calories in - fat stored - calories out = 0
OR
calories in - fat stored = calories out
Now in your original equation, assume that the person needs 1000 calories for their body to function normally. Also assume that the person eats 1000 calories a day. In your equation, since you assume that fat storage is a function of imbalance between needs and consumption, you get 0 fat storage.
However, in reality because of an insulin imbalance, what happens is this:
1000 calories are consumed.
200 calories are stored as fat.
This only leaves 800 calories to be used by the body. But wait, the body requires 1000 calories to function normally! Well there's two ways to compensate for that, either the person will consumed an additional 200 calories to get the body functioning normally, or the body will adjust it's needs, reduce the energy and movement of the individual, sleep more, etc.
Not all carbs are equal. The glycemic index for rice can be much lower than the glycemic index for bread or flour. (Glycemic index varies based on type of rice.)
I want to believe the obesity problem is more of a portion control thing, for example, when McDonald's opened, did a normal adult actually eat a hamburger and small fries for lunch instead of a big mac and large fries? But once again, I always have trouble finding any real data to verify my hypothesis.