How many calories usage to burn 1 pound fat?

food component	energy density
	kcal/g	kJ/g
fat	9	37
ethanol (alcohol)	7	29
proteins	4	17
carbohydrates	4	17
organic acids	3	13
polyols (sugar-free sweeteners)	2.4	10

Human fat tissue contains about 87% lipids, so that 1 kg of body-fat tissue has roughly the caloric energy of 870 g of pure fat, or 7800 kcal (9kcal/g x1000 x 0.87). Therefore one has to create a −7800 kcal deficit between energy intake and use to lose 1 kg of body-fat. In U.S. customary units, that is about 3500 kcal per pound. [2]

An Apple a Day for 10 years could add 3.5 stone weight

An apple a day keeps the doctor away, so the rhyme goes. But it could make you put on 3.5 stone over 10 years!

I worked out the maths today:-

• A small 100g eating apple has 47 calories.
• One pound of body weight is equivalent to 3500 calories.
  
• So if you eat 74 apples (3500/47) you could add a pound weight.
  
• An apple a day for a year could add 4.9 pounds (365/74) weight.
  
• In 10 years thats 49 pounds or 3st 7 pounds!

Twenty years ago I was 9st 13 pounds. In August 2006 I was 13st 7 pounds. So since 1986 I've eaten the equivalent of an apple every OTHER day - too much!

Isn't it amazing that everyone is not overweight!!

Genetics of eye colour unlocked

By Paul Rincon Science reporter, BBC News

Eye colour has always intrigued geneticists

Scientists have made a breakthrough in their understanding of the genetics behind human eye colour. (wiki)

They found that just a few "letters" out of the six billion that make up the genetic code are responsible for most of the variation in human eye colour.

The research, by a team of scientists from Queensland, Australia, appear in an issue of the American Journal of Human Genetics.

The findings are based on a genetic study of nearly 4,000 individuals.

One of the changes is like switching the light on and off, while the other is like changing the light bulb from brown to green Richard Sturm, University of Queensland

Differences in eye colour are largely down to "single nucleotide polymorphisms" (SNPs - pronounced "snips"); variations in the sequence of letters that make up a single strand of human DNA.

SNPs represent a change of just one letter in the genetic sequence. These changes, or mutations, in our DNA can have important consequences for how the gene gets physically expressed.

All the SNPs are located near a gene called OCA2. This gene produces a protein that helps give hair, skin and eyes their colour. And mutations in OCA2 cause the most common type of albinism.

Brown and blue

The study, which focused on twins, their siblings and parents, shows - conclusively - that there is no "gene" for eye colour.

THE DNA MOLECULE The double-stranded DNA molecule is held together by chemical components called bases Adenine (A) bonds with thymine (T); cytosine(C) bonds with guanine (G) Groupings of these "letters" form "code of life"; there are about 2.9 billion base-pairs in the human genome wound into 24 distinct bundles, or chromosomes Written in the DNA are about 20-25,000 genes which human cells use as starting templates to make proteins; these sophisticated molecules build and maintain our bodies

Everyone has two copies of a SNP. So there are several possible combinations, some of which are more heavily associated with, for example, blue eyes, than with brown eyes.

In short, these combinations strongly influence the colour of a person's eyes, but they are not the final word.

Dr Richard Sturm and his colleagues found three SNPs near the start of the OCA2 gene that were linked to blue eye colour.

"The SNPs we've identified in themselves are not functionally causing the eye colour change, but they are linked very, very closely to something that is," Dr Sturm, from the University of Queensland, told BBC News.

"When OCA2 is knocked out, there is a loss of pigmentation. The position of these SNPs right at the start of the gene means it is possible we're looking at a change in the regulation of the gene in people with blue eye colour."

Functional change

So these SNPs, at the start of OCA2, probably regulate how much of the pigmentation protein is produced by the gene. People with brown eyes might have a lot of this protein, while people with blue eyes have less.

However, the single letter changes involved in green eyes may actually produce functional changes in the pigmentation protein.

The researchers found SNPs at another position in the OCA2 region - linked to green eyes - that resulted in changes to amino acids (the building blocks of a protein).

"To use an analogy, one of the changes is like switching the light on and off, while the other is like changing the light bulb from brown to green," said Dr Sturm.

Altogether, the single letter changes identified in the study accounted for 74% of total variation in eye colour, the researchers said.

The study was a collaboration between researchers at the Queensland Institute of Medical Research and the University of Queensland, both in Brisbane.