Announcement

Collapse
No announcement yet.

Ask a biochemist.

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Originally posted by Molecular Grokologist View Post
    @ Mirrorball

    Your post seems accurate to me. I might add that the insulin theory doesn't really preclude the lipotoxicity theory. It could be that fat accumulates and is locked in by insulin but eventually fills up too much and begins to spill out.
    And the way out of this conundrum? Aside from just eating less? L-Carnitine, perhaps?
    I'm still trying to understand leptin.

    Comment


    • Originally posted by Molecular Grokologist View Post
      @ Mirrorball

      Your post seems accurate to me. I might add that the insulin theory doesn't really preclude the lipotoxicity theory. It could be that fat accumulates and is locked in by insulin but eventually fills up too much and begins to spill out.
      Thanks for reading it. AFAIK, in normal individuals, fat is locked in as long as blood sugar (and insulin) is high, so tissues are stimulated to burn sugar instead of fat, right? When that sugar is burned, insulin levels decrease and fat is released. If you eat 500 calories of fat and carbohydrate, the carbohydrate is burned first, then the fat. As long as you can burn 500 calories, you won't gain or lose weight. So how does insulin make you fat? If you eat 1000 calories of fat and just burn 500, the excess 500 calories, even though you didn't eat any carbs, will be stored, won't they? I'm not implying it's all about calories in, calories out, but the only fuel that gets stored is the fuel you didn't burn.
      Height: 5'4" (1.62 m)
      Starting weight (09/2009): 200 lb (90.6 kg)
      No longer overweight (08/2010): 145 lb (65.6 kg)
      Current weight (01/2012): 127 lb (57.5 kg)

      Comment


      • @PDL

        Well, low carb diets appear to make it better, the question is why. Fat adaptation helps corral serum FFA and burn it properly instead of having it float around causing trouble? I don't know.

        @ Mirrorball

        The hypothesis is that insulin will make the calories unavailable, thus making you tired/hungry and making you want to eat more so that your cells can get fuel. Over time, if calories are regularly unavailable between meals, the body may downregulate metabolism, potentially exacerbating the situation. Thus: adipose buildup, hyperphagy, carb cravings and lethargy.
        Give me liberty. Exploration of other options will be vigorously discouraged.

        Wondering something sciencey? Ask me in my Ask a Biochemist Thread

        Comment


        • Originally posted by Molecular Grokologist View Post
          The hypothesis is that insulin will make the calories unavailable, thus making you tired/hungry and making you want to eat more so that your cells can get fuel. Over time, if calories are regularly unavailable between meals, the body may downregulate metabolism, potentially exacerbating the situation. Thus: adipose buildup, hyperphagy, carb cravings and lethargy.
          But how would insulin make calories unavailable between meals? In normal metabolism, insulin is high and fat is unavailable only when blood sugar is high and thus calories from carbohydrate are available. When these calories have been burned up, insulin levels drop to basal levels, which makes calories from fat available again. The only way insulin could make fat calories unavailable between meals would be if fasting insulin was elevated, but it isn't in healthy individuals. For insulin to start having an influence between meals you would already have to have a disturbed metabolism. Unless I'm missing something?
          Last edited by Mirrorball; 04-15-2010, 10:28 PM.
          Height: 5'4" (1.62 m)
          Starting weight (09/2009): 200 lb (90.6 kg)
          No longer overweight (08/2010): 145 lb (65.6 kg)
          Current weight (01/2012): 127 lb (57.5 kg)

          Comment


          • Mirrorball, you are right. It is fasting insulin that is the problem. Trouble is, how do you get a "disturbed metabolism" as you said. I see no reason to believe that carbohydrate CAUSES the problem. Even Taubes admits it has to be refined carbohydrates or somehting similar. He mentions while sugar and while flower in particular... but I put the money on a combination of neolithic agents.

            Comment


            • Me too. Probably white sugar and white flour are the worst neolithic agents, but we can't neglect PUFA vegetable oils, and they are fats, not carbohydrates.
              Last edited by Mirrorball; 04-15-2010, 11:08 PM.
              Height: 5'4" (1.62 m)
              Starting weight (09/2009): 200 lb (90.6 kg)
              No longer overweight (08/2010): 145 lb (65.6 kg)
              Current weight (01/2012): 127 lb (57.5 kg)

              Comment


              • New question:

                We all know sat fat is good, but whilst we have a guideline to how many carbs are optimal, we have no indication of the upper boundaries of fats?!

                Basically today I got carried away at breakfast and ate about 100g of saturated fat content from creamed coconut, as well as my eggs etc.

                Surely not ideal? Whats the daily target?
                www.beatingorthorexia.co.uk

                No more diets. No more stress. Health made easy. Living made incredible.

                Comment


                • In general, as long as you keep intake below bowel tolerance (no fatty stools) and you aren't gaining weight (it's tough but possible if you eat a LOT of fat), things should be fine. I try not to go crazy with coconut fat all in one sitting because if it's not rapidly absorbed it can depopulate your gut flora to some extent, but it's not an end-of-the-world kind of thing. There is no 'insulin' for fat that we want to keep low, and no IGFR or TOR that we want to keep from triggering too much for aging purposes.
                  Give me liberty. Exploration of other options will be vigorously discouraged.

                  Wondering something sciencey? Ask me in my Ask a Biochemist Thread

                  Comment


                  • MG, did you ever watch those videos?

                    Comment


                    • No, I'm afraid I completely forgot. This afternoon when I get out of lab.
                      Give me liberty. Exploration of other options will be vigorously discouraged.

                      Wondering something sciencey? Ask me in my Ask a Biochemist Thread

                      Comment


                      • It's okay. There's a lot of jargon that went right over my head, but I got the general flavor of what he was saying. What I was really curious about is his take on the permanence of metabolic damage. He was basically making it sound as though there's no hope for people who've yo-yo dieted and such.

                        Comment


                        • I have a question on milk. I've read the post on milk and milk evidently has a high "Insulin Index." I am torn on milk because I like it and it seems to have a pretty decent nutrient profile (understatement) but if the goal is to keep insulin low and yet it spikes it quite a bit, then is the tradeoff worth it? Suppose we are talking about someone who needs to lose 10 lbs or so including some recomp (lose more fat and pick up a little muscle). Right now, I have gone to milk only after working out, but would include it more if I weren't struggling with the insulin question. Thanks!

                          Comment


                          • Milk is a healthy food for many, but it's not great for weight loss. I think you're right to restrict milk to PWO if you want to lose fat, although milk is good for gaining fat and muscle at the same time if you want to recomp later. Of course, if you really love milk, experiment with including it more in your diet. If your recomp goals are proceeding fine, then don't worry about it.
                            Give me liberty. Exploration of other options will be vigorously discouraged.

                            Wondering something sciencey? Ask me in my Ask a Biochemist Thread

                            Comment


                            • Ooooh, you know about TOR, eh?
                              I sort of advocate eating slightly lower protein than the norm becasue of several things including its effect on mTOR. Do you think that consuming large amounts of protein is a problem?

                              Comment


                              • No, but I think periodic intake of low/no protein is wise.
                                Give me liberty. Exploration of other options will be vigorously discouraged.

                                Wondering something sciencey? Ask me in my Ask a Biochemist Thread

                                Comment

                                Working...
                                X