An important one was protection from disease, suspected to be a consequence of the increased risk of infection that living in settlements brings.

ECONOMIST: Human evolution

While adequate weight gain during pregnancy is important for proper development of your baby, we now know that gaining too much weight is not good, as it can cause problems such as gestational diabetes, preeclampsia, increased risk of Caesarean section and infection, and more difficulty during labor.

CNN: How can I safely control my pregnancy weight gain?

But it said evidence revealed the general UK population was not at increased risk of TB, HIV or malaria infection from migrants, but some UK-born ethnic communities did have a higher risk of disease because of their links to countries where the diseases were endemic.

BBC: NEWS | Health | Migrants 'carry disease burden'

But it also increased the risk of a rare but deadly brain infection.

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