I have a remarkable and remarkably energetic neighbour who has been working in the catering trade for years. One wing of this service to the community is her
activity on the Foodcloud front. She has recently landed a job teaching refugees how to cook . . . with what's available in Irish stores . . . and Foodcloud? If you grew up in Ethiopia, y'might like to know what can
substitute for teff, like. That's started her on a rather more academic interest in food, diet and nutrition. A couple of weeks ago, I was plongeing the supper dishes and my phone rang (a rare event for Sudsy-no-pals me): "
please help, I need a reputable source to make sense of the blizzard of claims about protein in food".
On it, I replied,
do you want it by your 9 o'clock tomorrow class?Despite the answer being NO!, I sat down and started that night . . . and ran out of steam shortly after 0900 hrs the next morning. I surprised myself and that might be of interest.
Chef Bob on Protein
Well may you wail about truth, science, diet and marketing bullshit. There’s a reasonably entertaining BBC Podcast called Sliced Bread [whc prev] which takes a product (bike helmets, ecological diapers, sourdough bread), finds to experts and decides whether the Thing is:
SB the best thing since Sliced Bread or
BS marketing bullshit
case in point the High Protein cheese I found in LIDL last week [L]. Biggest number on the packet is 54g. Implying that this cheese is 54% protein, but the small print explains it is 54g per 160g pack-o-cheese. Nevertheless that's 34% protein while normal cheese is only 25%, so it does be High in protein - although how that is achieved is a mystery story for another day.
In our first world you’d have to work quite hard and eat quite peculiar to be short on protein. It’s different in sub-Saharan Africa if you get all your calories from cassava or corn-meal and you can’t afford lentils, let alone chicken. There is an argument that not all protein is the same because each source will have a different mix of the amino acid components of protein. BUT in general, protein is protein is protein unless you have a very narrow range of diet.
Proteins are made up of strings of 20 different amino acids. These building blocks have different properties and so build different proteins. They are not all equally common (in us or in food) but broadly the rare ones are rare everywhere and we only need a little.
- Serine, glycine, alanine are generally common.
- Cysteine, tryptophan and proline are rare.
- Leucine and isoleucine are very similar; as are (+-charged) Lysine & Arginine
- Glycine is tiny, tryptophan is large
- Glycine and glutamate also act as neurotransmitters
- Phenylalanine, methionine, leucine and isoleucine have a great affinity for fat
- Lysine, arginine, {acidic - charged) glutamate, aspartate are, in contrast, water soluble
Essential Amino acids: 9/20 of the amino acids have to be obtained by eating: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. The others can be manufactured internally by mix n matching from what the diet provides. But in the real world, this doesn’t make much difference because all food contains some protein and almost all proteins include some of all the 20 AAs – some foods are deficient in some AAs [next para] but for most of us, most of the time this is not a worry. Call BS if marketeers tell you different!
Complementary amino acids and protein combining
We have a copy of Diet for a Small Planet by Frances Moore Lappé from the 1970s. She was trying to get Americans to eat less meat but found that grains [rice, corn, wheat] are slightly deficient (for us) in lysine; while beans [+ lentils, garbanzos, peas] are slightly deficient (again for us) in methionine. She made a big story (and a lot of money) out of the idea that, by combining a diet of corn and beans together, Mexicans were able to complement the dietary deficiencies of each food group and make the combo a sort of super-food. She lived long enough to appreciate that this analysis was superficial, if not wrong, and realise that it was possible to get a diet adequate for usable protein fairly easily, so long as you lived in the country (and got to eat grasshoppers, salad-weeds, fruit). The urban poor, getting all their [starch heavy because cheap] food from the bodega on the corner were /are a different matter.
Protein requirements
International Recommended Dietary Allowance (RDA) for protein is 0.8 g per kg of body weight (bw), regardless of age. For me that’s 60-70 g or dietary protein every day. But meat is mostly water!! 100g ground beef will have only 15g of protein and 20g of fat. That much meat supplies about 10% of the calories required per day. So one quarter pounder won’t cut it: I need 4 or 5 hamburgers to keep up. Source. Obvs, I can trade some of those burgers for chicken or chick-peas. 100g of dried lentils are mostly carbs 63%, with protein at 25%; water at 10%; fat at 1%. More calories than meat because proportionately less water. Source. In contrast to what some are wont to say, old people with lower metabolic rate do NOT require less protein: rather ~50% more. Source.
PKU a special case
All babies are tested (with a heel-prick blood sample on a Guthrie Card) at birth for phenylketonuria PKU. Bloboprev If they test positive, it’s because they lack an enzyme which the rest of us use to metabolize excess phenylalanine, one of the 20 amino acids. Toxic by-products build up which prevent proper development of the brain. Solution: give the child a diet which is very low on phenylalanine (which is one of the 9 essential AAs so we all need some). But actually the prescribed diet is just “low protein” avoiding meat, eggs and dairy ?while supplementing the other 19 AAs as a pill. Also NO aspartame sweetener – because it is converted into phenylalanine ! Source.
A balanced diet WWI edition
check out Elsie Widdowson, who with others in WWII worked out that IF, on average, everyone got
- 125g fat
- 150g sugar
- 175g UK fruit [apples mainly]
- 50g egg [that's one egg] 7g protein
- 125g cheese 32g protein
- 450g animal protein 68g protein
- ad lib wholemeal bread, potatoes, cabbage
- each week!
THEN they'd be fine. The dietary protein sources thus provide for only about 2 days worth of the protein RDA. The brown-bread and spuds are doing a lot of heavy lifting here. Nevertheless, this diet kept 40 million Brits walking, working, thinking and fighting for 6 years so it can't be too far off the minimum requirements. Source:
bloboprev
