The Mathematics of Obesity

Hugh Pickens writes "The NY Times reports that Carson C. Chow, an MIT-trained mathematician and physicist, has taken a new look at America's obesity epidemic and found that a food glut is behind America's weight problem, with the national obesity rate jumping from 20 percent to over 30 percent since 1970. 'Beginning in the 1970s, there was a change in national agricultural policy. Instead of the government paying farmers not to engage in full production, as was the practice, they were encouraged to grow as much food as they could,' says Chow. 'With such a huge food supply, food marketing got better and restaurants got cheaper. The low cost of food fueled the growth of the fast-food industry. If food were expensive, you couldn't have fast food.' Chow and mathematical physiologist Kevin Hall created a mathematical model of a human with hundreds of equations, boiled it down to one simple equation, and then plugged in all the variables — height, weight, food intake, exercise. The slimmed-down equation proved to be a useful platform for answering a host of questions. For example, huge variations in your daily food intake will not cause variations in weight, as long as your average food intake over a year is about the same. Unfortunately, another finding is that weight change, up or down, takes a very, very long time. Chow has posted an interactive version of the model on the web where people can plug in their information and learn how much they'll need to reduce their intake and increase their activity to lose."

Comments

Corn and Processed Grains

[Riggity]

Newsweek had a nice writeup about obesity and consumption of processed grains that pairs well with this story.

she arrived in New York in 1934 and was "startled" by the number of fat kids she saw - "really fat ones, not only in clinics, but on the streets and subways, and in schools." What makes Bruch's story relevant to the obesity problem today is that this was New York in the worst year of the Great Depression, an era of bread lines and soup kitchens, when 6 in 10 Americans were living in poverty. The conventional wisdom these days - promoted by government, obesity researchers, physicians, and probably your personal trainer as well - is that we get fat because we have too much to eat and not enough reasons to be physically active. But then why were the PC- and Big Mac - deprived Depression-era kids fat? How can we blame the obesity epidemic on gluttony and sloth if we easily find epidemics of obesity throughout the past century in populations that barely had food to survive and had to work hard to earn it?

From my personal experience, I recently lost a lot of weight. The biggest shift I made to burn off fat was to drastically reduce how much grain I consumed weekly. I exercised about the same amount during the time, but the weight loss tracked pretty closely to my change in diet.

Re:Wrong Again

[codeButcher]

Apparently (IANA Dietician), some fruit contain more Fructose than Glucose, which makes the fructose load more problematic. See for instance http://en.wikipedia.org/wiki/Fructose_malabsorption, which has lists. Fructose is further problematic in that it chelates some other nutrients, like Zinc and Iron, removing them from the digestive tract and preventing them from being absorbed (can't find the paragraph on Wikipedia anymore, might be wrong.)

There's another article (http://newsroom.ucla.edu/portal/ucla/PRN-this-is-your-brain-on-sugar-ucla-233992.aspx) that did the rounds this morning about the negative effects of fructose on learning and memory.

Of course, this article also mentions omega-3 fatty acids, which are sorely lacking in the modern western diet that relies heavily on wheat, corn, soy and sunflower, as well as on meats, dairy and eggs "grain fed" on these crops instead of natural green pasture. This lack (or rather the imbalance between omega-3 and omega-6 content in modern food because of this) also contributes to obesity (and other "lifestyle diseases" like cancer and diabetes).

Duh?

[argStyopa]

This is news?
When I was a kid, and McDonald's were few and far between (early 70s) a McDonald's "meal" was a hamburger, fries, and drink.

That's a single hamburger, what is now a small fries, and a small beverage. That was a satisfying full meal for an adult. Is that even a kids meal any more?

Another example, I believe it was mentioned by a poster on slashdot. He was remodeling a 100yr-old farmhouse and he hadn't planned to, but found he had to rip out the cabinets as they were too small - the only plates that fit in the cupboard were the 9" (small) dinner plates, not our today-common 12" dinner plates.

Finally, I was talking with a friend that runs a restaurant. I asked him why their portion sizes were so massive. His response was that it was to camouflage the prices with extra food, since food prices were cheap - it's the labor that drives costs. If he offered a moderately-sized meal, it might cost $8. If he was to DOUBLE the amount of food on that plate, it would cost perhaps +$1. Conversely, cutting the amount of food in half would only save $1. Consumers are far more willing to pay $9 for a GIANT pile of food (they feel they're getting a bargain), than $7 for 1/4 the food. On the latter, they feel they're being ripped off.

Re:Duh?

[Jason Levine]

A few years back, I lost a lot of weight (about 80 pounds). One of the big things that helped was eating my meals on the small dinner plates instead of the big ones. This gave me the illusion of having more food than I really had. Try it sometime. Put the exact same amount of food on a big plate and on a little plate. Ask someone (who doesn't know they have the same amount) to tell you which plate has more food. Surprisingly (or perhaps not so surprisingly), the illusion of eating a lot of food versus very little food makes you feel fuller. About the only exception we made to the small plate rule was when we had salads, but we didn't load these up with unhealthy dressings and the like. The bigger plates became vehicles to transport more veggies into us.

Re:It really isn't sugar, that is just one avenue

[merlinokos]

I am not declaring that working only forty hours or less is bad; but lets be honest those we know who do more tend to get further;

Science and reality both say you, and those whose viewpoints you represent are deluded.
Labor, experiments, and industry all agree that a 40-hour work week is better for everybody - individuals and companies. Productivity by people who regularly work more than 40 hours per week is lower than those who work 40 hours.
The only reason people get ahead for working longer hours is because a generation of managers appears to have been taught to think that bums in seats = productivity. So longer hours = increased likelihood of promotion. It's a vicious cycle that's fuelled by people like yourself who speak with no understanding of how the human mind and body work. As a matter of fact, /. posted an article on this very subject 2 months ago today.

Re:Junk food is the problem

[TheRaven64]

Really? I spent a bit of time in the USA, in a variety of states, and I didn't find anywhere where it would have been difficult to afford to live on food cooked from fresh ingredients spending only a few dollars a day. Cooking a meal for a family would cost a lot less than taking them all to McDonald's.

I don't know where this idea that fresh fruit and vegetables are expensive comes from. They're the cheapest way of getting food, as long as you have time to cook (and 10-20 minutes a day is enough for that if you don't do anything too complicated).

Re:Get a copy of The China Study

[Anonymous Coward]

I'm living in China and I've lost a considerable amount of weight. It has little to do with diet. They eat substantially more fat and oil as a part of their diet than Americans do. But what they do do is exercise and a lot more of it. In the months I've been in China I've only ridden in an elevator one round trip. Not because I was avoiding them, but because I haven't seen them. My apartment up north required me to walk up and down 4 flights of stairs every time I left to go to work or really anywhere.

If I want to go somewhere, chances are good I have to walk.

What's more, the Chinese government provides free fitness equipment for people to use, and people do use it fairly regularly.

The suggestion that it's got something to do with diet is specious. They burn the calories they eat, and nothing more.

Re:Drugs

[Mindcontrolled]

Coming from Germany with its huge culture around sourdough bread I was shocked when I shopped for bread in a Californian supermarket for the first time. It was late already, I just came from the airport and I just wanted to grab something to make a sandwich. When I unpacked the stuff and took the first bite, it was... just horrible. When I studied the packaging, I learned that they obviously added a metric fuckton of molasses to the bread. What... the...??? The stuff was sweeter than some of the cakes I was used to.

Re:Get a copy of The China Study

[Kyont]

An honest question: Is smoking part of it? From what I've seen, a huge percentage of people in China smoke quite a bit. Obviously, this is hard on the lungs and heart in the longer term, but in the short term, it does burn more calories and tends to make people thinner. So are people healthier or do they just "look" healthier?

Exactly wrong

[Anonymous Coward]

Sorry, but this is wrong on so many levels. You see, while you get energy from stored fat, it is a quite energy intensive process itself if fat should be the main energy source. You can experience the "hitting the wall" effect yourself after a long endurance training. When the glycogen storage is depleted, the body switches completely to fat burning and suddenly you don't have any energy to go on and breathe much faster, might even faint.

Fat burning is meant to be an additional energy source, not the primary one. The reason why fat is stored is:

1) you have eaten too much food. Otherwise the fat would be all used up

2) You have got far too much fat mixed with carbohydrates in the food. Well, duh, the body takes what it can use right away and stores what it can use only with some effort.

Good grief, if this isn't a fantastic example of missing the forest for the trees....you have it almost exactly wrong.

Fat metabolism IS supposed to be the primary metabolic pathway. It is ideal for fueling the basal metabolic processes and low-level everyday activity. Why on earth would all mammals evolve the ability to store excess energy as saturated fat if the body wasn't fully prepared to run itself on that stored energy? Carrying around that excess weight is a hindrance, and if you have to have carbs present to make use of it I just don't see how it would confer the type of survival advantage that would bake it into the basic structure of our metabolism.
  Taken a step further - what fuels mammals during hibernation?
  If you look at the 'calorie requirement' calculators, the basal processes + everyday activity will always be the overwhelming majority of the calorie expenditure for a person during the day. Calories burned through exercise is substantially lower in all but the most extreme endurance athletes. this should be a pretty clear indication as to what is the more important metabolic process.

Your example of 'hitting the wall' during glycolytic exercise is also backwards. High-intensity glycolytic exercise is the EXCEPTION, not the rule. It is an activity that ISN"T supposed to happen frequently, and when it does happen it isn't supposed to be of a long duration. There is a very good reason we have only evolved the ability to store a fairly limited amount of glycogen - because historically, any more simply wasn't needed.

Taken together, IMHO these clearly illustrate why the low-carb/HIIT regimen is actually very successful as a strategy. Fat fuels your daily activity, with carbs 'topping up' the fairly minimal depletion of glycogen that occurs during the high-intensity activity. No one approach is ideal for everyone due to personal history etc, but there is a lot of science behind the low-carb/HIIT approach that very easily explains why it works well.

Re:Junk food is the problem

[mcgrew]

If potato chips are junk food, then so is a baked potato -- a potato is a potato. Grease with french fries or chips, butter with baked, no difference.

Meanwhile, I've never had a weight problem except the two years I was on Paxil and gained 40 pounds, and lost most of it despite trying not to when I stopped. Maybe this mathematician should add drugs to the equation. There's a woman that I see in the bar once in a while who used to be a crackhead. After stopping the crack she went from rail-thin to overweight in six months. And the number of drugs folks take today, and the number of new different drugs, especially prescription drugs is far more than in the '70s. No crack cocaine, no SSRIs, no ADD drugs (they hadn't even categorized ADD) etc. Pot makes some people fat and lots more folks are smoking it today. Rather than blaming "too much food" (I never knew many folks going hungry when I was a kid) maybe they should look at today's drug intake.

The "there couldn't be any fast food if food was expensive" in TFS is completely bogus. McDonald's has been around since 1940, Pizza Hut since 1958, long before they stopped paying farmers not to grow food and long before the obesity "epidemic". And when I was ten in 1962, a McDonald's hamburger, fries, and small coke was thirty two cents. How is that "expensive"? You'll pay ten times that much for the same thing today.

His history omits an important variable -- exports. After the government stopped paying farmers to not grow food, we started exporting so much that ADM's slogan is now "breadbasket to the world". We're not eating more because more's available, most of the extra food is being exported. It also neglects the size of soda, a small coke at McDonalds today is bigger than a large coke was in the sixties. Lots of caloric intake with nothing to curb hunger, a sure-fire way to obesity.

It also doesn't explain why poor people are more obese than middle class people. He would probably say "food stamps" but he'd be wrong. Poor folks are fat because cheap food is fattening --five pounds of potatos is only two bucks, TV dinners 89 cents, while expensive foods usually are far less fatteniing. Poor folks can't afford McDonalds very often, a small order of fries (1/3 of a potato) is a buck twenty while a five pound bag of raw potatos is only eighty cents more. Add a quarter pounder and a cole, and you'll pay the same price as two dozen burger patties and a loaf of bread at WalMart.

I'm sure the guy's maths are correct, but he's a mathematician, not a nutritionist, biologist, medical doctor, sociologist, or historian. A study like this would need input from all those fields and probably more to have any meaning. You don't ask a geologist about solar flares, after all.