any dieticians/nutritionists on here? I need help getting my head around calculating intake...

[MrsBigD]

Any help/pointers appreciated...

I've started studying nutrition and have to analyse food diaries. Easy... she thought... I can get my head around generally looking at the food diary and working out where the intake is lacking/good.

However... my stumbling block is...maths...

The asignment stipulates:

'use food tables to estimate the amounts of carbs, fats and proteins for the person for the day.

• Check

when you have filled the table with all foods for that day, add up the values for carbs, fats and proteins.

• Check (except for minor things like 'is cappucino a food' ;))

Convert these values to a percentage of total intake

• totally lost

I have tried tallying up the gram values and also tried converting the grams into kcal equivalent and then %'ing it against total daily energy intake.

Problem = it never tallies up! And if I compare the 2 different calculations they MOST DEFINITELY DON'T TALLY

e.g. in one of my food diaries
total energy/kcal of carb intake is 992 - aka 33.93% of total daily intake
which according to sources I've found is below the 45-60% of RDI intake/day
this compared to total grams of carb intake of 264.6g, which according to above mentioned sources is sort of within the RDI range of 230-310g/day...

HELP! [hang head in shame emoticon]

I'm not a nutritionist but I think you are trying to compare two different things, so they won't tally in % terms.... Do all carbs have the same calorie value per gram? (if not a stupid question )

I'm not a nutritionist either but I think where you're getting confused is the person has eaten almost 3,000 calories which is above the RDI so even though their percentage intake of carbs is below the RDI they've still eaten an amount of carbs in grams that puts them in the RDI range.

Just in case that's not entirely clear I'll try and work through the maths.

RDI of calories is 2,000 and this person's intake is 3,000 which means that they've eaten 150% of their RDI of calories. If we scale up the RDI range of grams of carbs per day by 150% we get 345-465 so you can see that the person has eaten less than this.

That was where I was going with my thinking - if 264g of carbs = 992 cals and carbs should represent approx 50% of total intake then total recommended cals should therefore be approx 2000 cals (992x2). So intake of carbs is at recommended level, fat/protein must be higher than recommended and represent the additional 1000 cals.

Does QueenS's and my explanation help mrsbigD?

It doesn't work as you can't add percentages - unless they are of the same thing. ie can add 35% of calorie intake are fats and 40% of calorie intake are carbs - so 75% fats and carbs.