The association between time spent sitting and mortality has been found in other studies, and the link persists even after accounting for other physical exercise.
The email says that the pictures are from a zoo in California where the mother tiger had lost triplets and the grieving was so bad that it began to affect her health.
Still, Dr. Bernstein said the study was strong not just because of its size but because it weighed factors other than malformations, such as birth weight, that also affect the health of the baby.
America's health-reform bill, which Congress passed this year, requires restaurant chains with 20 or more outlets to put the calorie-content of items they serve on the menu.
The youngest was the extraordinary case of a six-year-old Peruvian, who suffered precocious puberty and gave birth to a healthy boy by caesarean in 1939.
Her two boys and two girls were healthy and doing well after being born July 6 by Caesarean section in what doctors said was a rare occurrence of multiple births.