Underfed pups in larger litters have decreased insulin levels and are lighter.

<p>Increasing the litter size of lactating dams from six (normally fed) to 10 pups (underfed) lower the offspring body weight in 7 days-old pups of both sexes. Data are presented as the mean ± SEM, analyzed by the student t-test, *** <i>p</i> < 0.001.</p>