3 ms·

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

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.

oasisbob 15y ago
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.
- TheSOB88 15y ago
  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.
  - oasisbob 15y ago
    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.
    - pyre 15y ago
      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.
      - oasisbob 15y ago
        Fructose can be metabolized to glycogen via DHAP and glyceraldehyde. IIRC, it's a limited pathway though.
    - TheSOB88 15y ago
      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?
      - oasisbob 15y ago
        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.
deleted 15y ago
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oasisbob 15y ago

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.

TheSOB88 15y ago
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.
- oasisbob 15y ago
  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.
  - pyre 15y ago
    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.
    - oasisbob 15y ago
      Fructose can be metabolized to glycogen via DHAP and glyceraldehyde. IIRC, it's a limited pathway though.
  - TheSOB88 15y ago
    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?
    - oasisbob 15y ago
      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.

deleted 15y ago

[deleted]