long story short... installed new bike riding program on my phone that also does a calorie count if you put the food in...

Made me think about home cooked food and its calories..

is there an easy way to work out the calorific content of things you cook ?

As far as I'm aware the energy is measured by burning it and seeing how much energy it gives off (in the lab). This seems an odd way of working it out if you ask me. My thoughts being something like "petrol" would burn very well but would do very little in the way of giving a human energy (extreme example I know). Other foods must be smilar though.. I don't know but lets say burning a sample of a fibrous food would give off "E" amount of energy because the whole of it is burned in the lab burning process, however the human metabolisim/digestion might only break down 10% of what is eaten so would actually only get "( E / 100 ) x 10" or something along those lines.

The same confusion then comes with working out from packet/box information and how it is affected by preperatioin and cooking. Suppose olive oil is "E" amount of energy for 50ml. You put 50ml into the frying pan and fry off something. Some of the oil will stay in the pan, some will evapourate into the air around it so effectively your dish will only have "E - loss to air / pan" of energy and not the full amount...

am I just over confusing the issue or are these valid points ?

Steve

No Steve, It certainly confuses me too. How also do you equate that some people are very efficient at converting food to energy (metabolic rate etc?) and others much less so.

Totally unrelated to this, but when I read Steve's post it got me thinking to an incident at an airport a few years ago where I was charged for excessive baggage. The point I made to the woman on the check in desk was that there were people in the queue that probably weighed more than me and my baggage put together, and yet I have to pay extra dollars because my bag is slightly overweight. I think that was the icing on the cake for Mexico to be honest!

Sid

Sid because that would be size-ist ! its extreme logical conclusion would be you being stuck in a burning building and them sending a fireman who only weighs 7 stone and is unable to carry you to safety because it saves fuel when they are driving around... etc... :-)

Steve

Thanks for that :o)

I'm not size-ist or any of the ists, I'm a nice guy really, albeit a little eccentric so I am told. It's just something that always had me thinking that's all.

Sid

Steve, your comments are probably the same as many peoples, with regard to 'burning' food to determine the calorific content. But this method has been superseded by simple calculation.

The accepted method of calculating energy content of food is to measure the amount of carbs, protein and fat in the sample. Then, for every gramme of each:

carbs has 4 kcal

protein has 4 kcal

fat has 9 kcal

so 100g of (dry) rice would have about 400 kcals.

Meat is about 20% protein (the rest is fat, water and connective tissue) so 100g of meat would be 400/5 = 80 calories (just for the protein).

There are books that give the carb, protein and fat content of a huge range of food, and any dish can be have its calorific content calculated.

Sid, I know what you mean about large people, I used to fly to Londonderry in N. Ireland, on a small plane (one row of seats one side of the aisle, two the other). They load passengers on these by balancing (roughly) the size/weight of the people, so one large person sits on the single seat side, and two smaller people on the other side of the aisle!! What amused me was that there was always a large flight attendant on these flights, no doubt to 'adjust' the ballast. [I have to admit I was always allocated a 'single seat side' seat. What are they trying to say??]. Luckily the flight was too short to have food served, that would have meant adjusting the balance again, no doubt!! LoL

Thanks Lapis will make working things out a bit easier that way :-)

the meat being 80% fat sounds a lot though ?

Steve

no, not 80% fat, but only 20% protein, average. Most of the rest is fat, water and connective tissue. There is a lot of water in meat. When cooked, even chicken looses 35% weight as water, and there is quite a bit left in the meat after cooking, or else it would be like eating wood! Obviously the fat content varies, as would connective tissue (everything which isn't protein, fat or bone).

It does point to how little protein there is in meat, though.

LOL! What did they do when there was turbulence? Tell everyone to stand up in the middle of the aircraft and jump up simultaneously?

Sid

ah again thanks for the clarity, didn't realise so much of meat was water..

I'm thinking about something like a steak trimmed of fat and most of it being red meat rather than marbling of fat etc.. is that still only 20% protein and lot of it water ?

Steve

I think it would vary quite a bit, but its worth noting that a steak is not all meat protein. I don't have my book to hand, so I can't give you a definitive figure, maybe google it, but the important thing to note is what I have said.

Using this method, it is possible to 'balance' any meal with the accepted proportion of carbs, fats and protein, and maybe surprisingly, its the protein levels which are higher than recommended in many dishes.

The first googled site I looked at said 25% protein in most cuts of beef, so not far from the 20% I suggested.

Regards the water content of meat, think when you cook Mamta's Chicken Jalfrezi how much moisture suddenly appears from the chicken.

Surely there must also be a direct correlation"

High cost/high flavour/slow breeding/low water content meat TO low cost/low flavour/fast breeding/high water content (plus some added in the factory) meat; just look at what supermarkets admit to being the (added) water content of their packs of ham!

Winton

The reason I started thinking about calories again (the application on my phone for tracking bike rides) thinks I should eat 3300 calories a day. Yesterday I did a 26.5 mile bike ride up some serious hills which it mapped and worked out I'd burnt off another 2500 calories.. so yesterday (according to the app) even after eating a big omelette for breakfast ( http://postimage.org/image/290b2wlqc/ ) and then a great big roast dinner, some toast and a few beers it says I still needed to eat another 2000 calories !

Steve

So that doesn't that mean you are using your calorific reserves, i.e. with a 26 mile bike ride you have found the holy grail of a weight loss situation! But on the other hand you are unlikely to be doing a 26 bike ride every day - unless there is something you are not telling us, bring on Steve at the velodrome 2012!

Winton

lol I'm not out on 26 miles every day.. some times nothing.. some times an hour doing 3 miles up a steep hill.. sometimes 15 miles around a reasonably flat route.. maybe a big ride at weekend etc.. plus riding the short distance to and from work... means I can eat well and still get fitter/thinner.. :-)

Steve