Yitzchak Schechter, PsyD, published an article in 2012 titled Creating a Resting Place for the Shechina: Ideals, Expectations and Reality in Marriage in which he described how a study was conducted to assess differences in BMI "weight categories in a sampling of self-identified Modern Orthodox, Modern Yeshivish and Yeshivish women."
He writes, "Many surmised that the Modern Orthodox sample would be lower in weight due to increased exposure to media and the “Hollywood” ideals of thinness and beauty. Others predicted that the Yeshivish sample would lean towards thinness, due to the pressures of shidduchim. In actuality, the Yeshivish and Modern Yeshivish groups were skewed towards thinness to a statistically significant degree. More important than the socio-religious comparison, this finding potentially highlights that unique internal systems (e.g., shidduchim) can have even greater influence than external ones (e.g. media exposure).
Incidentally, if you want to lower your BMI you might do well to read the following article.
The Daily Mail reports Almonds, perfect snack for health: Handful a day can keep heart healthy and beat the flab, results of six new studies conclude.
Then again, it might pay to have a higher BMI as cardiologist Dr. Carl Lavie reports his findings.
Q: You cite a 2013 finding that people with a body mass index of 25 to 30, which is considered overweight, have the lowest mortality rate. [BMI is a measure of body fat based on weight and height; 25 or greater qualifies as overweight, while 30 or greater is obese.]
A: That was a meta-analysis of 97 studies of 2.9 million people, and they analyzed greater than 270,000 deaths. They showed the absolute best survival was in the 25-to-30 BMI range. That group had a six per cent lower mortality than did the normal BMI group.