Height is indeed more influenced by genetic than environmental factors - weight depends more on the environment ( nutrition and diet ).


The study quoted in the " Daily Mail " certainly involved many ( 450,000 ) participants ; they were recruited from the " UK Biobank study " of half a million 40-69 years olds registered with the NHS. It excluded individuals of non-white ancestry or born outside the UK and Republic of Ireland.


The analysis - after written consent - was from questionnaires including " recall of birthweight " and past or current diseases in answer to the question " Has a doctor ever told you that you have had any of the following conditions ? ".



The study - as originally published - did claim " robust associations " between " season of birth, birth weight, pubertal timing, adult body size and educational attainment ".


Explanation(s) for these associations were less certain - giving " support for the hypothesis that season of birth has on childhood growth and development " and " while other mechanisms may contribute to these associations, these findings are consistent with a possible role of in utero vitamin D exposure " ( depending on amount of sunlight ).


Clearly Arthur, Graham, and Michael - and also many commenting on the " Daily Mail " report - have different experiences. Even if this Cambridge University observational study is confirmed by other work, as the findings are not fully explained, they don't appear at this stage to be worthwhile noting for family planning by future parents .