The finding is based on an analysis of the stress response of 86 people born in Motherwell in 1967 and 1968 whose mothers were advised to eat one pound of red meat per day and to avoid carbohydrate-rich foods.
Previous studies had found that children of women who ate such diets in late pregnancy were more likely to have foetal growth restriction, raised BP and glucose intolerance.
The researchers tested the stress response of the adult 'Motherwell babies' using a three-minute mental arithmetic test and a five-minute public speaking test.
Their BP and heart rate were measured before and after the test, and samples of blood and saliva were taken to measure changes in their cortisol levels.
BP rose by an average of 14mmHg and heart rate increased by six beats per minute. Plasma cortisol levels also went up, by 28 per cent in men and 9 per cent in women.
Those whose mothers reported the highest intake of meat during late pregnancy had the greatest increase in cortisol.
The researchers concluded that the mothers' unbalanced diet during the late stages of pregnancy had had a lifelong effect on their children's ability to cope with stress.
They suggested that this finding was of particular concern as raised cortisol levels had been linked to increased risk of developing hypertension and diabetes.
Lead researcher Dr Rebecca Reynolds, senior lecturer at the University of Edinburgh endocrinology unit, told the conference that this study added to the evidence of the importance of the maternal diet: 'One of the ways in which it can have long-term effects is by permanently altering stress hormone levels.
'Given the recent popularity of low-carbohydrate and high-protein diets, such as the Atkins diet, these data suggest that these diets should be avoided during pregnancy.'
Endocrine Abstracts 2006; 11: P594