Pregnancy weight gain: marmoset and tamarin dads show it too.
Level 5 - mechanism / opinion, no new human data
Animal research with no human data
PubMed 16810338 · doi:10.1098/rsbl.2005.0426
What was done
Researchers monitored the weight of expectant male common marmosets (Callithrix jacchus) over five months and expectant male cotton-top tamarins (Saguinus oedipus) over six months of mate pregnancy, comparing them with non-expectant control males.
What was found
The abstract reports no numerical values or effect sizes. Expectant males of both primate species showed significant weight increases across the pregnancy period, whereas control males did not.
Why it matters
It provides evidence in non-human primates that expectant fathers in species with high paternal investment gain weight during their mate's pregnancy, potentially preparing for the energetic demands of infant care.
Limits
The abstract lacks sample sizes, exact weight changes, variance metrics, and p-values. It is an animal study and cannot be directly generalized to human paternal physiology.
Cited by
- supports Studies across both animal models and humans find that males tend to gain weight when they become fathers.
- supports A study of expectant tamarin monkeys fed a standardized diet showed that expectant fathers gained more weight than control male monkeys who were not expecting offspring.