Scientists are pondering over the fact that British breasts are getting bigger. Over less than a decade, the average bra size has grown from a 34B to 36C.
According to top class retailers Marks & Spencer, a quarter of all its bras sold are a D cup or above. This figure has doubled in three years. Now, as per consumer demands in its range, which used to end with a G cup, now goes up to a J.
They are not the only ones. Lingerie company Bravissimo has even introduced three different K cup bras.
Now, it would be easy to blame this on an increase in cosmetic surgery. Breast implants remain the most popular procedure and last year, around 10,000 British women underwent the operation.
Still say experts ranging from dieticians to gynecologists, the reasons why breasts are expanding are complex. They can differ from obesity to hormones and from alcohol to environmental factors.
Now why this all matters is because size does matter. There is a direct connection with the health of our breasts and of our bodies as a whole, say experts.
Nutritionist Marilyn Glenville says she has seen clients who have increased by a cup size after being put on hormone replacement therapy (HRT). This was to help them cope with menopause.
She suggests breast tissues are being encouraged to grow by the unusually high levels of estrogen into the body from the HRT, and she certainly does not believe this is a harmless side-effect of dealing with menopause.
The female breast is said to contain cells called oestrogen receptors. These are stimulated by the presence of oestrogen to produce more mammary tissue.
A simple increase in size alone could be an added advantage, yet it is also possible that stimulating these cells artificially after the menopause (when natural estrogen levels are dipping) could also contribute towards breast cancer.
"Putting women on HRT is giving the body estrogen at a stage when it would not normally have it," says Glenville. "The more exposure we have, the more likely we are to get breast cancer."
Cancer Research UK gives that 70 per cent of breast cancers are driven-driven. And according to its website: "The bottom line is that HRT does increase breast cancer risk."
Glenville notes other lifestyle changes that can increase the amount of driven flooding the body.
"Our daughters are reaching puberty earlier - sometimes as young as eight. This means they will have much more exposure to driven in their lifetimes.
"Women are also having fewer children so the body is exposed to higher levels of driven in the long term, as during pregnancy and breastfeeding driven levels in the body are lower", points pot Glenville.
Consultant gynecologist Peter Bowen-Simpkins, medical director of the London Women's Clinic and spokesman for the Royal College of Obstetricians and Gynecologists, agrees that theoretically hormones could bring about a change in the figure." If men took driven as they used to in the early days of treating prostate cancer, they developed noticeably larger breasts", he offers an example.
At the same time, he does not believe the levels of artificial hormones that women take now are enough to make a significant contribution to breast size.
This brings in another view. Could 'false' hormones be affecting our body via the environment?
Xeno-oestrogens are chemicals from pesticides or plastics that mimic the effect of estrogen. These are fat-soluble and store themselves in the body. In our highly processed society, xeno-oestrogens are found everywhere from food to cosmetics. Currently, scientists are unsure of how dangerous they are.
The Department of Environment, Food and Rural Affairs (Defra)warns that there are serious environmental concerns about the way artificial hormones affect our health, wildlife and the food chain as a whole.
Yet, a spokesperson for Defra says: "Many substances, including common ones such as water, salt and alcohol, can cause changes to hormone systems. A ban on the basis that something has this property could deprive society of many useful chemicals."
Glenville adds : "We are talking about a cocktail of toxins so it's hard to pinpoint what is going wrong. But many products, from lipsticks to tampons to spermicides, contain xeno-oestrogens - and we are applying them directly to our bodies.
"We know these chemicals will be having some impact on men, but on women it is more physically obvious", she says.
In the midst of all this, one plausible reason stands out stoutly. Obesity is a major problem in the UK. The Medical Research Council gives that 50 per cent of adults are overweight and 20 per cent are classified as obese. Those extra pounds of flesh could be one reason for the boom time of British breasts.
Professor Michael Baum, an expert in breast cancer says :"Fat is laid down on breasts as much as thighs or bottoms. We are in an epidemic of obesity. It isn't surprising women's measurements have increased."
Glenville recommends noting body-fat percentage before fixing a diet. "Are you over-fat or over-weight?" she asks. "Breast tissue is adipose or fatty, that's why weight gain shows up so quickly there. To lose weight from your bust you need to lower your sugar intake and eat less processed food as this will keep your blood sugar level stable so you can burn fat."
High sugar foods force the body to increase its insulin output. Too much insulin helps your body to store energy as fat and makes it more difficult for your body to break down those fat stores when you try to lose weight.
This brings out another clue to increasing bra size: alcohol. "We are raising a generation that does not care about how many units they consume," says Glenville.
"Alcohol is full of sugars that will elevate your blood sugars and cause them to release unstable levels of insulin. It also has a toxic effect on liver function. This means estrogen and other hormones can end up being recirculated around the body and perhaps reabsorbed instead of being broken down in the liver, if that organ has been damaged by too much alcohol."
Yet there are some positive reasons why the British breast size has increased. "More women are taking up aerobic exercise and building up their pectoral muscles, which can affect cup size," says a Marks & Spencer spokesman.