Sunday, September 02, 2007


The article below says that both skinnies and fatties have fewer children. The conclusions are however naive. The authors assume that the effect is due to lower fertility. That fatties might be less popular as partners and hence late starters in having children does not seem to be considered. The results may also be dated. I sometimes get the impression that it is MAINLY fatties who are having children these days

Body Mass Index in Adolescence and Number of Children in Adulthood

By Jokela, Markus et al.


Background: Body weight is associated with reproduction and related behaviors, but it is unknown whether it has significance for fertility differences in the general population. We examined whether adolescent body mass index (BMI; kg/m2) predicted the number of children in adulthood 21 years later.

Methods: The participants were 1298 Finnish women and men (ages 12, 15, and 18 years at baseline) followed in a prospective population-based cohort study (the Cardiovascular Risk in Young Finns) from year 1980 to 2001.

Results: There was an inverted J-shaped association between BMI and the number of children, such that underweight adolescents had 10-16% fewer children in adulthood, overweight adolescents 4-8% fewer, and obese adolescents 32-38% fewer than individuals with normal adolescent weight. This association was similar in women and men, and independent of age, education, urbanicity of residence, and timing of menarche (in women). Adolescents with low or high BMI were less likely to have lived with a partner in adulthood, which partly accounted for their decreased number of children. The influence of adolescent BMI was independent of adulthood BMI in women but not in men. Age at menarche also predicted the number of children, such that women with early or late menarche had more children than those with average age at menarche.

Conclusion: Underweight and especially obesity may have a negative impact on fertility in the general population. The increasing prevalence of obesity in children and adolescents may represent a concern for future reproductive health.

Epidemiology. 18(5):599-606, September 2007


Anything that is popular will of course be condemned by the self-ordained superior folk so prophecies of doom about ultrasound scans of babies in the womb are entirely to be expected. Could it even send your babies mad? The following article examines that and draws reasonable conclusions

Prenatal Ultrasound Scanning and the Risk of Schizophrenia and Other Psychoses

By Stalberg, Karin et al.


Background: Prenatal ultrasound exposure has been associated with increased prevalence of left-hand or mixed-hand preference, and has been suggested to affect the normal lateralization of the fetal brain. Atypical lateralization is more common in patients with schizophrenia. We evaluated possible associations of prenatal ultrasound with schizophrenia and other psychoses.

Methods: We identified a cohort of individuals born in Sweden 1973-1978. During this period, one Swedish hospital (Malmo University Hospital) performed prenatal ultrasound on a routine basis, and all individuals born at that hospital were considered exposed to ultrasound. Children born at hospitals where ultrasound was not used routinely or selectively were considered unexposed. We used Poisson regression analysis to estimate the effect of ultrasound exposure on the incidence of schizophrenia and other psychoses.

Results: In all, 370,945 individuals were included in the study, of whom 13,212 were exposed to ultrasound. The exposed group demonstrated a tendency toward a higher risk of schizophrenia (among men, crude incidence rate ratio = 1.58 [95% confidence interval = 0.99-2.51]; among women, 1.26 [0.62-2.55]). However, men and women born in several of the 7 tertiary level hospitals without ultrasound scanning also had higher risks of schizophrenia compared with those born in other hospitals. For other psychoses there were no differences between groups.

Conclusions: No clear associations between prenatal ultrasound exposure and schizophrenia or other psychoses were found. Other factors related to place of birth might have influenced the results.

Epidemiology. 18(5):577-582, September 2007.


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 and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].

Trans fats:

For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.


No comments: