In India's case, the two major problems around nutrition are - wasting (low weight for a given height) and lack of pre-natal and post-natal care (the pregnant woman is undernourished, not aware of the importance of breastfeeding)
Wasting has a lot to do with our eating habits- mostly vegetarian (the ones who eat non-veg also take a major part of their dietary intake as protein-deficient carbohydrates-rich grains and gravies). Plus the protein-rich options are available at a premium due to market failure- both veg (pulses and legumes), and nonveg (eggs, meat, fish). The govt never subsidized the production of legumes, animal husbandry products, and micronutrient-rich fruits and vegetables. Millets which were traditionally a part of Indian food (Bajre ki roti in the north to Raagi Mudde in the south) were systematically ignored by the middle class in their quest for finer grains (rice and wheat).
And as far as pregnant women and newborn childcare are concerned, there is extremely poor understanding around it due to lack of funds. Anganwadi workers are ill-trained, scantily paid, and work without any clear supervision. Awareness about anaemia in the growing girls, the importance of family planning (an important factor being the break between successive pregnancies) and nutrition requirements is just not there yet. The GoI launched a PoSHAN scheme in 2018 to address the issue of malnutrition and the biggest cost header for the scheme after 1 year was IT. State Govts are equally irresponsible where women and child development is considered to be a less lucrative portfolio.