Roughly, in expectation, making yourself underweight during pregnancy should therefore be costing your kid 6 IQ points or so. (Plus additional risk of infant sickness and death, of course; being a preemie is bad for risk in pretty much every way.)
I would say that a world in which that looks worth it for your kid’s future success and happiness is a pretty rigidly classist world. This becomes starker the worse neonatal medical care in your country is (and I don’t have a good gauge for that in Nigeria.)
Let’s keep in mind that going hungry while pregnant is costing your child IQ points.
Underweight women have a 1.5x risk of having a low birth weight child and a 1.3x chance of preterm birth. https://academic.oup.com/ije/article/40/1/65/661543. Low birth weight kids are about 5 IQ points lower in adulthood than normal birth weight kids. https://www.ncbi.nlm.nih.gov/pubmed/23896861. For premature babies, that difference is about 11 points. https://www.medscape.com/viewarticle/461571_3
Roughly, in expectation, making yourself underweight during pregnancy should therefore be costing your kid 6 IQ points or so. (Plus additional risk of infant sickness and death, of course; being a preemie is bad for risk in pretty much every way.)
I would say that a world in which that looks worth it for your kid’s future success and happiness is a pretty rigidly classist world. This becomes starker the worse neonatal medical care in your country is (and I don’t have a good gauge for that in Nigeria.)