T Nation

Fructose question

My current diet is 35% carbs, 35% protein, 30%
fat, and I’m getting half of the carb cals
from low GI fruit (blueberries, grapes,
oranges, etc.), or about 18% of total cals
from fruit. The other half of carbs are from
yams, corn, maltodextrin etc. My question is,
what percentage of carbs coming from fructose
would be considered “too much” for optimal
results? I realize fructose isn’t the
greatest carb source (I don’t think it is a
“bad” source either), but certain fruits do
have health promoting properties, so I don’t
want to give up fruit entirely. So how much
is ok? And how much is too much? Thanks.

While it can vary from person to person, I’d say that more than 50-75 grams per meal can have negative effects. Some can handle a little more and some can handle a little less. You’d have to eat A LOT of fruit to get that much fructose in anyhow. BTW, there are quite a few vegetables that contain fructose too. Yams or sweet potatoes as you mentioned. Funny how these vegetables have long been eaten by bodybuilders and yet aren’t questioned. It’s just a fear that’s been ingrained into the minds of some people. Hope this helps.

Thanks for the response, Cy. I read your
article on fructose, and I thought it was
quite good. I don’t think fruit is a “bad”
source of carbs like many bodybuilders do.
I think (most) fruit is an ok, or so-so carb
source and has health benefits in general. But
I think there is something to be said for the
fact that fructose does not replenish muscle
glycogen as well as other carb sources
(glucose etc). Am I wrong? Maybe you and Bill
Roberts (and maybe John Berardi) should have a
“carbohydrate wars” debate, as Bill seems to
be quite down on fructose. From my own
experience, fructose seems to be ok while
dieting. But I haven’t been able to determine
how well it works while in a hypertrophy phase

  • which is why I’m asking. Basically my
    question is: to maintain optimal levels of
    muscle glycogen, is there some limit on the
    percentage of carbs from fructose. Maybe
    that’s what your response answered, but it
    wasn’t clear to me. If Bill reads this maybe
    he’ll provide a counter opinion.

Why you tryin ta instigate a fight and shit du? Joking. Actually, you’re correct. It isn’t as good at repleneshing muscle glycogen as other monosaccharides. At the same time, it isn’t as if you get zero glycogen storage from ingesting fructose. I thought the issue was whether or not it’s detrimental to the process of reducing body fat.

What I’m looking for is people’s experiences
or any research tidbits that might help me
figure out how much (total or percentage) of
carbs (compared to other carb sources) can be
consumed from fruit/fructose before it will
negatively impact gains during a hypertrophy
phase. If I eat one meals carb portion from
fructose I doubt it will impact gains; but if
I eat 4 or 5 meals carb portions from
fructose it probably will. Where in there
is the right balance. Someone go wake up Bill
and John for their epinions. (Please.)
Anyone else who has an opinion on this is
welcome also.

Cy, I don’t think Free like you…LOL. Free, the only time you need to be concerned with percentages is post-workout. That is the only time your body is in a muscle glycogen storage phase. Post-workout, you want very little fructose (as in none or maybe up to 15% of your total carbs, which are preferrably maltodextrin). The rest of the day, you are free to do as you will. Fructose in liver glycogen friendly. If your liver is full, it goes to circulation, if that is full, it goes to fat storage. In the case of other carbos during this time, pretty much same thing. As long as you keep your carbs below 50 on the glycemic index, it doesn’t matter what you eat. If you choose anything over 50, again, it doesn’t matter what you eat either, you will get fat, whether fruit or starches. Just focus on the index during the day, with no regard to source. Post-workout use maltodextrin only or add in up to 15% of your carbs with a high glycemic fruit. Enjoy your fruit during the day, just stay under 50 GI.

Thanks Bodz, that info was helpful. As far as
Cy is concerned, I think he writes some damn
good articles … I wasn’t tryin to bust his
ass, he just didn’t answer the question I was
asking. LOL