Author Topic: Calories in food components  (Read 2337 times)

Calories in food components
« on: 24 June, 2010, 08:44:57 pm »
Tapping the community wisdom .........

I'm slowly learning, in a piecemeal fashion, about diet for cycling - current wisdom/fashion seems to suggest a diet of 50% carbohydrates, 30% proteins and 20% fat.

I'm starting to look more attentively at food labels, but I'm confused. These commonly state the kcal value of 100gms of the contents and then break down the 100gms by percentage into carbs, protein, salts, fats etc. but give the proportions in weight not kcal. But the different types of food type have different kcal/gm values don't they? So if something is 300kcal per 100 grams and contains 40gm of carbs it doesn't follow that you're getting 120kcal from the carb content does it?

So is there a definitive kcal value per xgrams of carb/protein/fat etc.?

Gus

  • Loosing weight stone by stone
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Re: Calories in food components
« Reply #1 on: 24 June, 2010, 08:58:24 pm »
1 gram protein/carbohydrate = 4 kcal / 17 KJ

1 gram fat = 9 Kcal/ 38 KJ

1 gram alcohol  7kcal/ 30 KJ

So 40 gram carbohydrate = 160 kcal

hellymedic

  • Just do it!
Re: Calories in food components
« Reply #2 on: 24 June, 2010, 09:07:31 pm »
Wot Gus typed.
Remember something that is 93% fat free can be 7% fat and the proportion of the product's calories from fat may be from 15% to 100%!

Re: Calories in food components
« Reply #3 on: 24 June, 2010, 10:33:15 pm »
Wot Gus typed.
Remember something that is 93% fat free can be 7% fat and the proportion of the product's calories from fat may be from 15% to 100%!
Yes, that's in essence what I was thinking might be the case!

Thanks Gus; particularly the bit about the alcohol - I think!

Re: Calories in food components
« Reply #4 on: 24 June, 2010, 10:36:40 pm »
1 gram protein/carbohydrate = 4 kcal / 17 KJ

1 gram fat = 9 Kcal/ 38 KJ

1 gram alcohol  7kcal/ 30 KJ

So 40 gram carbohydrate = 160 kcal

Hey that's great - just what I need. I suspected fat would be "denser" in kcal than carbohydrate; I wasn't so sure about protein though. Thanks

inc

Re: Calories in food components
« Reply #5 on: 25 June, 2010, 10:18:10 am »

I'm starting to look more attentively at food labels, but I'm confused.

So are most people, it's because the labling is designed to be confusing while complying with the  weak legislation. A lot of fat in processed products is trans fat  Trans fat - Wikipedia, the free encyclopedia and if you are interested in your long term health best avoided. So that would include cakes, biscuits, pies processed meats etc. Processing also removes a lot of the vitamin and mineral content to the point where it has to be added later. I wouldn't be too concerned about the ratio of carb/protein/fat just miss out the junk food and you will by default eat nutritionally better. From my ( limited ) Audax experience it appeared to me that some riders finish despite their feeding regime  than because of it. I suspect cafe stops are popular more for the mental, rest and social aspects.

simonp

Re: Calories in food components
« Reply #6 on: 25 June, 2010, 05:17:42 pm »
I think you have the protein content too high and the fat too low.

A normal 15% protein diet should be perfectly adequate for an endurance athlete.  30% protein is very high.