Understanding Bodyweight and Glycogen Depletion (article)

Shropshire1959
Shropshire1959 Posts: 982 Member
in Fitness and Exercise
Hi all - just found this interesting article.......

http://justinowings.com/understanding-bodyweight-and-glycogen-de/
Quick take — If you diet or are planning to start a diet, understanding the relationship between bodyweight and glycogen (Glycogen is carbohydrates as stored by your body) depletion is paramount.

Your body stores energy as fat and glycogen. Whereas fat stores can vary dramatically from person to person, your body can only store so much energy as glycogen.

Glycogen requires water to be stored. In the initial stages of diet/caloric restriction and exercise, your body depletes these glycogen stores, reducing your bodyweight from the elimination of both the weight of the stored glycogen and the weight of the water. Note that nowhere in this process is the much-desired loss of fat!

Thus, even as it will feel good to shed 5 – 10 lbs. simply from a few days of exercise mixed with a caloric-restricted diet, the weight loss will be primarily from a reduction in glycogen stores and water. In other words, what you’ll have lost in the beginning is really little more than water weight.

Take heart in understanding the relationship between glycogen stores and bodyweight as an improved understanding will help you set realistic expectations on whatever diet or exercise regiment you are undertaking in 2009.

A deeper dive:

I first learned about the relationship between stored carbohydrates and water retention from Gary Taubes’ Good Calories, Bad Calories. The gist is that for every gram of stored carbohydrate (Stored as glycogen) in your body, there is a set amount of additional water storage that is required.

Taubes had pinned the carb/water storage ratio at two grams of water per one gram of carbohydrate. A random Googled source (Vitanet) pins it at 2.7 gram water per gram of glycogen. I found a research paper titled, Glycogen storage: illusions of easy weight loss, excessive weight regain, and distortions in estimates of body composition, which offers the following data on the ratio:

Glycogen is stored in the liver, muscles, and fat cells in hydrated form (three to four parts water) associated with potassium (0.45 mmol K/g glycogen). . . .

Glycogen losses or gains are reported to be associated with an additional three to four parts water, so that as much as 5 kg weight change might not be associated with any fat loss.

Replies

  • 26MORE2GO
    26MORE2GO Posts: 21 Member
    NICE. THANKS FOR THE INFO.
  • neandermagnon
    neandermagnon Posts: 7,436 Member
    Gary taubs is not a reliable source

    the body does store glycogen and it's important to understand how this works to avoid freaking out over water weight gains and losses

    but a lot of people believe stuff like you have to be glycogen depleted to burn fat.... no you don't.... your body balances the burning of fat and the burning of carbs (including the sugar in your blood and your glycogen stores) - so as you go about your daily life and when you exercise you're burning both fat and carbs... whether you have a net gain or loss in body fat depends on whether you're eating at a deficit, at a surplus or at maintenance.

    Low carb diets can actually be counterproductive, because when glycogen depleted the body only has fat to burn and not carbs... there's a limit to how much energy the body can get from fat at any one time, so if you're running off only fat you are not running at maximum efficiency. So while you may feel that much more exhausted while working out when glycogen depleted, you're not actually burning that many calories.... compare that to working out with plenty of carbs in your system, you'll have a lot more energy and be able to power through a workout and burn a greater number of calories in a shorter time. If you're burning more energy (calories) overall, it'll be easier to create and maintain the deficit that you need for fat loss. And the same with general activity... if you feel more energetic as you go about your day, you'll burn more calories than if you feel exhausted all day. You'll burn about the same amount of fat either way, but with carbs in your system you'll be burning carbs and fat, i.e. a greater number of calories in total.
  • Shropshire1959
    Shropshire1959 Posts: 982 Member
    Gary taubs is not a reliable source

    the body does store glycogen and it's important to understand how this works to avoid freaking out over water weight gains and losses

    but a lot of people believe stuff like you have to be glycogen depleted to burn fat.... no you don't.... your body balances the burning of fat and the burning of carbs (including the sugar in your blood and your glycogen stores) - so as you go about your daily life and when you exercise you're burning both fat and carbs... whether you have a net gain or loss in body fat depends on whether you're eating at a deficit, at a surplus or at maintenance.

    Low carb diets can actually be counterproductive, because when glycogen depleted the body only has fat to burn and not carbs... there's a limit to how much energy the body can get from fat at any one time, so if you're running off only fat you are not running at maximum efficiency. So while you may feel that much more exhausted while working out when glycogen depleted, you're not actually burning that many calories.... compare that to working out with plenty of carbs in your system, you'll have a lot more energy and be able to power through a workout and burn a greater number of calories in a shorter time. If you're burning more energy (calories) overall, it'll be easier to create and maintain the deficit that you need for fat loss. And the same with general activity... if you feel more energetic as you go about your day, you'll burn more calories than if you feel exhausted all day. You'll burn about the same amount of fat either way, but with carbs in your system you'll be burning carbs and fat, i.e. a greater number of calories in total.

    Thanks .. There is so much 'data' out there and so difficult for my BS radar to process.. we need to wipe down the Interweb with bleach and start again :-)

    The problem is (well mine, for one) is that a little knowledge is dangerous, so you read something that 'sort of' sounds right when held up against ones own limited knowledge and if it re-enforces it - it's held up as GOOD Data otherwise is seen as BAD.

    Oh well many thanks for the input and I'll go search the cess pool for more Brain Food.
  • ihad
    ihad Posts: 7,463 Member
    Gary taubs is not a reliable source

    the body does store glycogen and it's important to understand how this works to avoid freaking out over water weight gains and losses

    but a lot of people believe stuff like you have to be glycogen depleted to burn fat.... no you don't.... your body balances the burning of fat and the burning of carbs (including the sugar in your blood and your glycogen stores) - so as you go about your daily life and when you exercise you're burning both fat and carbs... whether you have a net gain or loss in body fat depends on whether you're eating at a deficit, at a surplus or at maintenance.

    Low carb diets can actually be counterproductive, because when glycogen depleted the body only has fat to burn and not carbs... there's a limit to how much energy the body can get from fat at any one time, so if you're running off only fat you are not running at maximum efficiency. So while you may feel that much more exhausted while working out when glycogen depleted, you're not actually burning that many calories.... compare that to working out with plenty of carbs in your system, you'll have a lot more energy and be able to power through a workout and burn a greater number of calories in a shorter time. If you're burning more energy (calories) overall, it'll be easier to create and maintain the deficit that you need for fat loss. And the same with general activity... if you feel more energetic as you go about your day, you'll burn more calories than if you feel exhausted all day. You'll burn about the same amount of fat either way, but with carbs in your system you'll be burning carbs and fat, i.e. a greater number of calories in total.

    Excellent explanation.

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