Sunday, November 12, 2006

Kiddy speech: A finding that is less strange than it seems

Below is a recent journal abstract:

Mother and father language input to young children: Contributions to later language development

By Nadya Pancsofar & Lynne Vernon-Feagans

There has been little research comparing the nature and contributions of language input of mothers and fathers to their young children. This study examined differences in mother and father talk to their 24 month-old children. This study also considered contributions of parent education, child care quality and mother and father language (output, vocabulary, complexity, questions, and pragmatics) to children's expressive language development at 36 months. It was found that fathers' language input was less than mothers' language input on the following: verbal output, turn length, different word roots, and wh-questions. Mothers and fathers did not differ on type-token ratio, mean length of utterance, or the proportion of questions. At age 36 months, parent level of education, the total quality of child care and paternal different words were significant predictors of child language. Mothers' language was not a significant predictor of child language.

So the mothers do the talking but it is dads who influence the speech skills of their children. Wacky? Yes. But there was a confounding variable that was apparently not measured: IQ. I suspect that it was only the high IQ fathers who talked much to their kids and, given that IQ is highly heritable and highly involved in verbal skills, their kids showed best language development. Political correctness causes most medical researchers to ignore influences like intelligence and social class, thus leading to many weird "findings" and a grave loss of understanding about what is actually going on

Obesity masks the big picture

(A moderate view from an Australian GP -- from "The Australian" of Nov. 4th, 2006)

By Simon Cowap

"Oh well,doc," said my dejected patient "my weight is 80kg, my BMI is 30 and my waist circumference is 98cm. I guess that makes me just another statistic in the obesity epidemic."

Stories about obesity abound. There are dire predictions for what this means in terms of increased rates of type 2 diabetes, hypertension, cardiovascular disease, sleep apnoea, osteoarthritis and certain cancers. We hear a lot about how it is affecting our children. with 19.5 per cent of boys and 21 per cent of girls being classified as obese. Interestingly though, 20 per cent of women and 9 per cent of men aged 18-24 attending GPs are actually underweight. The obesity epidemic is perhaps a bit oversold.

The more frightening statistics usually refer to "the overweight and obese". People are classified as overweight if they have a Body Mass Index - weight in kilos divided by their height in metres squared - of between 25 and 30. Those who are are obese have a BMI rating of more than 30. Overweight Australians usually greatly outnumber the obese, and there is a big difference between the health impact of a BMI of 27 and one of 35.

Weight is a significant personal and public health issue. But our response often seems to be either working ourselves up into a frenzy without really knowing where to go next, or to become rather punitive in a way that risks increasing that already high proportion of young women who are underweight. While being concerned about obesity, we need to be realistic, and the reality is that achieving durable weight loss is difficult. We are fighting against powerful neuroendocrine mechanisms that defend body fat stores, an evolutionary adaptation to the scarcity of pre-history. Weight loss programs are regarded as a success if they achieve weight loss of 3 to 5 kg, or 5 to 7 per cent of body mass, for a year or more.

Drugs like the currently heavily promoted orlistat (Xenical) produce a mean weight loss at one year of approximately 2.9kg. Diet and exercise remain the cornerstone of weight control for most people. The best composition of weight loss diets remains controversial, but the bulk of evidence supports either high carbohydrate/low fat or high protein/moderate carbohydrate diets. Very low calorie meal replacements can be used to augment the effect of diet. Exercise is an important component, and most successful regimes include 30 minutes of moderate intensity exercise daily. As most of us expend only 5 to 10 per cent of our daily energy intake on exercise, even doubling it does not have an enormous impact. Even if weight is unchanged though, increasing exercise is still very effective in reducing cardiovascular and diabetic risk.

Likewise, not all kilojoules are created equal. A diet high in vegetables, pulses, grains and fish - the `Mediterranean diet' - may be good for your health independently of any effect on weight. Given that focusing purely on weight, waist circumference and BMI can be rather demoralising, it is important to remain aware of the global health impact of any lifestyle changes you make.

Even weight loss medications work best in conjunction with diet and exercise. Only silbutramine and orlistat are used as long term agents here. They are suitable for people with BMI above 30 and those with a weight-related disease. Taking silbutramine in additional to modifying diet and exercise provides a weight loss of about 4.5kg at one year. For very obese people, with a BMI of more than 35, a form of surgery known as laparascopic adjustable gastric banding is a more effective means of weight loss. Weight is a serious health issue. But it's not the only one. I'd rather be slightly overweight, eating well and exercising than smoking and sedentary with a BMI of 25.

Europeans fat too

Europeans think there are more obese adults and children today than there were five years ago, according to a new poll by the European Union. However the proportion of people who consider themselves overweight, at 38%, is roughly the same as in 2002. An average EU citizen now weighs 72.2kg (11st 5lb) and is 1.7m (5ft 7in) tall. About one in five have changed their eating habits in the last year, with most of these trying to eat more fruit and vegetables, and less fat.

More than 80% of those polled totally agreed or tended to agree that obesity was on the increase, and felt that governments should do more to tackle the problem. Some 55% thought their weight was about right. The proportion of people considering themselves overweight varied from country to country - from 25% in Slovakia to 50% in Luxembourg. In the UK the figure was 41% - 5% down on 2002. Women were more likely than men to consider themselves overweight - 44% compared with 32%.

On average, respondents said they spent more than six hours a day sitting down. Only 22% said they had performed a lot of physical activity in the seven days before they took part in the poll. One in three, on average across the EU, said they had performed no physical activity in their leisure time. Just over half of respondents said they did not have enough time to take advantage of the facilities for physical activity in the area where they lived. People from Hungary, Luxembourg and Denmark were heaviest for their height, and Italians and French were the lightest. People in Luxembourg were on average 2.7kg (6lb) heavier than in 2002, while in the Netherlands they were 0.8kg (1.75lb) lighter. People in the UK were 0.2kg (0.4lb) lighter.



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter? It is just about pure fat. Surely it should be treated as contraband in kids' lunchboxes! [/sarcasm].

9). For a summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and no lasting harm from them has ever been shown.


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