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Comment by michael_dorfman | Hacker News Reader

The only place on the campus where employees pay for food is from a vending machine. The pricing strategy is based on nutrient content, again according to the Harvard pyramid plan. For the vended products, you pay:

  one cent per gram of sugar
  two cents per gram of fat
  four cents per gram of saturated fat
  one *dollar* per gram of trans fat

That's very cool. I'd love to see this concept get wider usage.

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It saddens me to see that sugar costs less than fat.

ObReference to "Good Calories, Bad Calories."

Well technically, sugar costs more per calorie than fat. As one gram of sugar is 4 calories and one gram of fat is 9 calories.

Right, but it's not the total calories that folks like me and mslyuter are worried about. Sugar and other carbs, when digested, raise blood sugar levels, which in turn raises insulin. Then, blood sugar gets sucked into fat cells and converted into fat simply because of the insulin. So those calories don't even get a chance to be used in their original form before they're stored as fat.

IMO the various ways blood sugar affects your appetite and your body chemistry are probably more responsible for the obesity epidemic than the high-calorie content of fatty foods.

So those calories don't even get a chance to be used in their original form before they're stored as fat.

Sure they do! Don't forget about glycogen.

I don't know if we're understanding each other... I'm saying that there are carbs that get transformed into fat. These calories, by definition, do not get used until the fat is released from that cell. Which could be a loooong time.

You're right, glycogen is another place that carbs can go. But unless you're exercising there probably isn't a lot going there.

Lipogenesis is legitimate, but it's not the primary pathway for carb metabolism if you have a healthy diet. Glycogen is the primary way that blood sugar levels are regulated, and your body greatly prefers glycogenesis to lipogenesis.

If you're exercising, your body doesn't build glycogen; rather, it shuts down the metabolic pathways for glycogenesis because burning glycogen while building it is very inefficient. (It's a form of hysteresis.)

... painting with broad strokes because my background is in biochemistry, not nutrition.

I think the difference here is that glucose can be converted to glycogen, but fructose can't. Both high-fructose corn syrup and sucrose are a combination of approx. 50/50 fructose/glucose (the most common HFC in use is a 55/45 split; sucrose has a chemical bond between the two sugars, but HFC doesn't). My understanding is that when most people refer to sugar, they are talking about sucrose, and not glucose in isolation; therefore, ~50% of 'sugar' can't be converted to glycogen.

Fructose can be metabolized to glycogen via DHAP and glyceraldehyde. IIRC, it's a limited pathway though.

By exercising, I meant exercising regularly. In my understanding, you don't make new glycogen unless your glycogen stores are down. And the body can only store about 3 pounds of glycogen from what I've read.

So what I'm saying is if you're mostly sedentary, eating a high-carb diet, your blood sugar levels will rise to the point that insulin is secreted. And then some of that blood sugar will be converted to fat, and its energy will be 'lost' - it won't be used unless blood sugar levels go down again and glucagon is released. But many people eat way too much and too often for this to happen, and they just keep on packing on the pounds. Thus, carbs causing weight gain while fat gets the blame.

I mean, think about it. All the sugar that comes into your bloodstream from, say, two bowls of cereal in the morning. You have about 3 cups of milk, 3 cups of grains. This is a pretty big amount of carbs that gets digested very quickly. Then you drive to work and sit on your bum for 4 hours. Don't you think some of that carbohydrate energy could be converted to fat before your next meal?

Insulin is secreted every time you eat. It's not a bad thing, it's a very fundamental part of regulating your blood sugar. (Ask someone with type I diabetes -- it's a royal pain to control blood sugar manually.) It's released whether you're active, sedimentary, eating a healthy diet, or junk food.

When you eat breakfast in the morning, you're most certainly replenishing glycogen. While you sleep, it's the primary source of blood glucose. Your body will prefer to replenish the glycogen before beginning lipogenesis.

So... there's no such thing as too much insulin?

There is, if a person's diet is consistently high in sugary foods. They can build up insulin resistance as a result of a constantly high insulin level, and ultimately develop type 2 diabetes.

ObReference, haven't seen that in a while! Former rec.arts.books reader or device driver writer?

Heh, neither, but I'm pretty sure I got it (or terms like ObJoke) from some usenet group back in the day.

Unfortunately it seems to penalize people who choose to eat more fat vs. carbs.

That's a problem with the entire green/yellow/red color-coding system at Google as well - the labels seem to be in line with the common belief that whole grains = always good and dietary fat = always bad.

Then again, it's not really difficult to figure out from the list of ingredients whether food is in line with your personal dietary belief system, so the color-coding system isn't really all that valuable to begin with.

"personal dietary belief system", that's how I imagine Google employees talking about food.

That problem stems from the source that Google chose to base their system off - the Harvard Pyramid. They wanted to be as least controversial as possible (aka popular conventions) so whole grains are viewed as healthy, and fatty foods aren't. That's the principle we've been hammered from the government and food associations since forever. Unfortunately, it's wrong, and just a little research reveals it. But people will always want to refute you... because they've been so used to it, and they don't want to give it up.

Unfortunately, not being controversial is also the same as being wrong in this case

I'm very very sympathetic to this view. I eat a high-fat diet, and have for over a year. But Google is probably right to act conservatively here. Don't blame Google for following the Harvard Pyramid, blame the Harvard Pyramid. They're the ones with the responsibility to update the status quo.

You should probably look at the Harvard Pyramid before making judgments based on Google's interpretation:

http://www.personal.kent.edu/~cearley/ChemWrld/foodpyramid/H...

They recommend eating lots of healthy fats such as olive, canola, and peanut oil. They also have refined carbohydrates in the "use sparingly" category.

Thanks, but I did. And I'm still not criticizing their interpretation (which seems like a good faith read of the pyramid). I just disagree that the HP is the only way to eat healthily, and I'm mixed on whether the HP is a generally healthy way to eat.

Also, you may wish to dismiss me as crazy. I eat almost exclusively from the top left triangle. :)

It's not the whole grains I'd be worried about. "Granola bars" are sugar/candy bars disguised with some granola and "healthy" labelling (usually upselling the fiber content).

Indeed. Quaker chewy granola is identified (by price -- $0.15) as a good food, which may be true if you're out hiking, but as part of an urban lifestyle, granola bars are a glycemic disaster.

By contrast, someone who eats an otherwise moderately healthy diet can eat the caloric equivalent of several granola bars worth of walnuts -- identified by google as a "yellow" food -- with no ill effects, and certainly no insulin spike.

No, since (as someone pointed out elsewhere in this thread), a gram of sugar has less than half of the calories in a gram of fat.

If Alice and Berta both choose to consume exactly 2000 calories a day, but Alice chooses a low-fat diet while Berta chooses a low-carb one, then Berta will pay less according to that system. So it's not really a problem that sugar costs less; low-fat diet are still cheaper.

(Duh. I meant of course "low-carb diets are still cheaper")

It would be very cool if it was correct. How is sugar the cheapest?

Agreed. The idea is very good, but the implementation sucks.

Not so sure about the quality of the idea. It's very hard to objectively quantify nutritional value to the precision required, igniting controversy about the right price point.

It's good to make sure healthy food is available, but ultimately only people themselves can decide what to eat - the fact that candy and snacks with saturated fats are available in the first place illustrates that very clearly.

I'd love to see sample prices from said vending machine. I.e. 2oz bag of m&m = $1 or snickers bar = $2

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