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The liver converts fructose into glucose. While glucose is not essential, energy is, and glucose is the preferred energy for cellular metabolism (glycogen). Ou
by jp555 13y ago
The liver converts fructose into glucose.
While glucose is not essential, energy is, and glucose is the preferred energy for cellular metabolism (glycogen). Outside being in a sustained energy-surplus fructose is of little consequence.
Energy-balance (digested food calories - energy exerted living) is magnitudes more important than the macronutrient content of your diet.
- mberning 13y agoThat is a big oversimplification. You can go watch Lustig's 'Bitter Truth' video for the biochemical details. The TL;DR is that fructose has some special properties which allow it to permeate your cells and organs whether they want the fructose or not. There are also some very nasty byproducts from the metabolism of fructose that are not present when metabolizing glucose by itself.
- jp555 13y agoI've seen it. His data shows it's the increase of calorie consumption over time. This was mostly sugar (Honey, table sugar, HFCS are all around half fructose), but it was the sustained increase in energy intake over years that's the cause. Even if fructose has some special role in promoting more of a fat-storage bias in metabolism, it's due to eating too much, not due to the fructose; eating less (or scaling activity with food intake) solves both problems.
- natrius 13y agoWhat if eating fructose makes you eat more? That has certainly been the case for me.
- jp555 13y agohow do you know that? There are so many possible confounding variables that make that claim doubtful.
- natrius 13y agoWhen I avoid carbs, I lose weight. I don't get cravings for the foods that normally led me to overeat. It's an anecdote, so feel free to take it with a grain of sugar, but Taubes and Lustig improved my life a great deal.
- jp555 13y agoEvery gram of stored carbs (glycogen) gets stored with ~3g of water. By cutting carbs you use up stored carbs and rapidly lose this water-weight. This is why low-carb diets work so well at first, But it's not fat you're losing.
- natrius 13y agoThe first week or two of weight loss is indeed mostly water, but I weight 40 pounds less than when I started avoiding carbs. It works for me.
- bollockitis 13y ago> Energy-balance (digested food calories - energy exerted living) is magnitudes more important than the macronutrient content of your diet. That's a convenient fallacy which is so often repeated that it is simply assumed to be true, but some -- such as Gary Taubes, Dr. Lustig (the author of this article), Dr. Eric Westman, and others -- argue the exact opposite: the macronutrient content of one's diet matters very much. Different macronutrients provoke differing endocrinological responses. Our bodies are biological, not mechanical machines, and we process carbohydrates differently than fats or protein. It isn't controversial and it shouldn't come as a shock. New research is showing that the hormone cascade brought about by certain foods -- and by adipose tissue itself -- has an enormous impact on our health. The problem is that people want to oversimplify nutrition into universal equation which assumes that everyone is the same, and they often cite epidemiological nutritional studies -- notorious for being inaccurate and unreliable -- to do so. The truth is probably more complicated: the diet that keeps one person healthy might make another fat and sick, and it's primarily dependent upon genetics, not physics. For more on this, read any of Taubes's books. They are quite compelling. Dr. Lustig has written a few himself.
- jp555 13y agoI prefer to read biochemistry books. this is my current bible http://www.amazon.com/Advanced-Nutrition-Metabolism-Sareen-Gropper/dp/0495116572 http://www.amazon.com/Advanced-Nutrition-Metabolism-Sareen-G... Every single hospital-ward double blind clinical trial over the last 100 years says exactly the same thing: net energy balance is what determines how fat you are, no matter the macronutrient content of the diet. Nutrition's role in lifelong health is a LOT more complicated. What your lifetime Vitamin D levels probably matters a lot. But over a lifetime, eating a diet of mostly whole foods, and in amounts scaled to activity is going to give you benefits that will completely drown out what kind of fat you ate over the last 30 years or if you ate pop tarts for breakfast. My point is, if you're fat and unfit, it's not any particular macronutrient's fault.
- a8da6b0c91d 13y agoI thought thyroid hormone and resting metabolism played into it to some degree. Like if you go too low on protein, the metabolism will crash and the person will get even fatter.