Nutrition is particularly important during pregnancy to ensure your health and the health of the baby. It's normal to gain weight during pregnancy—not just because of the growing fetus, but because you'll need stored fat for breast-feeding. The Institute of Medicine (IOM) recommends a gain of 25 to 35 pounds in women of normal weight when they get pregnant; 28 to 40 pounds in underweight women; and at least 15 pounds in women who are overweight when they get pregnant. The IOM has not given a recommendation for an upper limit for obese women, but some experts cap it as low as 13 pounds. If you fit into this category, discuss how much weight you should gain with your health care professional.
However, many fortification programs in low- and middle-income countries are regional or voluntary and, thus, might have a limited nutritional impact at the national level (76). Although many efficacy trials show benefits of fortification interventions, scaling up fortification is limited by inadequate coverage and resources (13, 77, 78). Evidence for impact is also affected by suboptimal programming, low-bioavailability fortificants (e.g., reduced iron powder), poor consumption rates, weak enforcement mechanisms, and inadequate monitoring (76, 79, 80). More research is needed to evaluate the long-term impact of fortification and biofortification programs (75). In addition, there is also growing concern about fortifying and promoting food vehicles that have adverse health consequences when consumed in excess, such as salt and sugar, given the rising prevalence of overweight, obesity, and noncommunicable disease (81–83).

  Schools (and universities)  ↓/NC anemia, ↓ Fe-deficiency anemia, ↑/NC MN status [Hgb (↑ if anemic), ferritin, zinc, retinol], ↑ MN status [folate, riboflavin, 25(OH)D, iodine], ↓ PTH, ↓ goiter prevalence, ↓ MN deficiency (vitamin A, B-12, C), ↑ bone mineral accretion, ↑/NC weight gain/BMI, ↑ MUAC, ↑ gut inflammation, ↓/NC respiratory symptoms and diarrheal morbidity, ↑ fitness (for Fe-deficient subjects), ↑/NC short-term cognitive function  ↑ Hgb (↑ if anemic), ↑ serum ferritin, ↑ total body Fe, ↑ urinary iodine concentration, ↑ serum zinc, ↑ aerobic power, NC net energetic efficiency     

If you lose weight suddenly or for unknown reasons, talk to your health care professional immediately. Unexplained weight loss may indicate a serious health condition. And even if it doesn't, simply being underweight is linked to menstrual irregularity, menstrual cessation (and sometimes, as a result, dental problems, such as erosion of the enamel and osteoporosis) and a higher risk of early death.
Poor nutrition may be one of the easiest conditions to self-diagnose. Look at the food pyramid and the suggested servings. Look at your diet. Are you getting the recommended daily amounts of fruits and vegetables? Enough calcium? Read the labels and compare what you eat to what you need. You may discover that even if your weight is ideal, you are not getting enough nutrition.

Our findings identified gaps and limitations in the evaluation, scope, targeting, and delivery platforms of nutrition interventions in low- and middle-income countries. First, the monitoring and evaluation of nutrition programs that reported on women's nutrition outcomes was generally inadequate. Many of the studies we identified included small-scale efficacy trials. Although there were many large-scale programs that targeted women and adolescent girls with nutrition-specific and nutrition-sensitive approaches, they lacked rigorous evaluation. Whether the evidence about women's outcomes was limited because they are not systematically measured or because they are not well reported is not clear. Negative results are often not published, and many evaluations of nutrition interventions that are conducted by the same groups responsible for implementing them are typically presented positively. This may have also skewed our findings. More intentional research-quality program evaluation, including of large-scale programs, would provide a stronger evidence base. Of the studies identified in this review, many reported on short-term findings such as changes in knowledge, dietary behaviors, and program coverage. They were limited in their ability to report clinical and anthropometric outcomes for women, the duration of those outcomes, and the feasibility of scaling up programs. There is also a need for systematic, long-term evaluations of interventions whose effects on nutrition outcomes are more distal (e.g., nutrition education compared with micronutrient supplementation). The effects of multisectoral interventions are even more complex to measure. However, frameworks exist to evaluate complex interventions (102) and could be utilized to evaluate the impact of interventions across the life course.