Nutrition in Pregnancy Case Study: Designing a Balanced Meal Plan for Sarah at 15 Weeks’ Gestation

Overview

At 15 weeks, Sarah is at the start of her second trimester. From this point her energy needs rise, the fetus grows quickly, and her needs for protein, iron, calcium, folate, choline and omega-3 fats all increase. Sarah is healthy, her BMI is normal and she has no allergies or aversions, so she does not need a restrictive diet. She needs a balanced, nutrient-dense eating pattern with slightly more energy, safe food handling and a daily prenatal vitamin.

This guide does five things. It explains how to design Sarah’s meals, shows them as a Balanced Plate, summarizes the dietary guidelines for pregnancy, works out her kilocalorie target, and breaks the plan down by food group: meat and beans, fruits and vegetables, grains, milk, fluids and carbohydrate.

How to design the meal

A step-by-step approach makes sure the plan is individualized and meets current guidelines:

1. Assess the client. Sarah is in her second trimester with a normal BMI, a negative medical history and no allergies or aversions, so no condition-specific changes such as for gestational diabetes or anemia are needed. Her recommended total weight gain for a normal BMI is 25–35 lb (11.5–16 kg), about 1 lb (0.45 kg) per week in the second and third trimesters (Institute of Medicine [IOM], 2009).
2. Estimate energy needs. Add the second-trimester increase of about +340 kcal/day to her pre-pregnancy needs. For Sarah this comes to about 2,300–2,400 kcal/day (see the Kilocalories section).
3. Choose a food-group pattern. Use the USDA MyPlate pattern that matches her calorie target (2,400 kcal) to set daily amounts for each food group.
4. Spread intake over 3 meals and 2–3 snacks. Smaller, regular meals help with nausea, heartburn and energy levels, which are common as the uterus grows.
5. Build each meal on the Balanced Plate. Fill half the plate with vegetables and fruit, a quarter with whole grains and a quarter with lean protein, and add a dairy food and water on the side.
6. Check for key pregnancy nutrients and food safety. Include foods rich in folate, iron, calcium, choline, iodine and DHA. Avoid high-mercury fish, raw or undercooked foods and unpasteurized products.
7. Evaluate and adjust. Track Sarah’s weight gain at each prenatal visit and adjust portions if she gains faster or slower than recommended.

Sarah’s Balanced Plate

The featured meal is Sarah’s dinner: baked salmon, brown rice, steamed broccoli and roasted sweet potato, with fresh mango, a glass of low-fat milk and water. It provides about 770 kcal, roughly a third of her daily needs, and covers every food group in a single meal.

Why this meal works for Sarah

• Salmon provides high-quality protein and the omega-3 fat DHA for fetal brain and eye development. It is a “best choice” low-mercury fish (FDA & EPA, 2021).
• Brown rice provides complex carbohydrate, fiber and B vitamins.
• Broccoli is rich in folate, vitamin C (which helps her absorb iron) and some calcium. Sweet potato provides beta-carotene (vitamin A) and potassium.
• Mango adds vitamin C and natural sweetness without added sugar.
• Low-fat milk provides calcium, vitamin D and protein for fetal bone development.
• Water supports the increase in blood volume and amniotic fluid and helps prevent constipation.

Dietary guidelines for pregnant women

Several authorities guide nutrition in pregnancy: the Dietary Guidelines for Americans, 2025–2030 (USDA & HHS, 2026), the Dietary Reference Intakes (IOM, 2005a), and the American College of Obstetricians and Gynecologists (ACOG). Their key recommendations for Sarah are summarized below.

Foods and substances Sarah should limit or avoid

• Alcohol: no amount is known to be safe in pregnancy.
• High-mercury fish: avoid shark, swordfish, king mackerel, tilefish (Gulf of Mexico), bigeye tuna, marlin and orange roughy. Limit albacore (white) tuna to 6 oz per week.
• Raw or undercooked foods: cook eggs until the yolk is firm, cook fish to 145°F (63°C) and meat and poultry to safe temperatures. Avoid raw sprouts.
• Listeria risks: avoid unpasteurized milk, cheese and juice. Heat deli meats and hot dogs until steaming.
• Caffeine: keep it under 200 mg/day, about one 12-oz cup of coffee (ACOG, 2010).
• Added sugars and highly processed foods: keep added sugars under 10% of calories and choose whole, minimally processed foods (USDA & HHS, 2026).

Supplementation: Sarah should take a daily prenatal vitamin that contains at least 400 mcg of folic acid, 27 mg of iron and iodine. Iron is the nutrient that is hardest to meet from food alone.

Kilocalories

Energy needs in pregnancy are estimated as pre-pregnancy needs plus a trimester-specific increase (IOM, 2005a):

• First trimester: no additional kilocalories
• Second trimester: +340 kcal/day
• Third trimester: +452 kcal/day

Sarah’s height, weight and activity level are not given. Assuming a typical pre-pregnancy need of about 2,000 kcal/day for an adult woman with a normal BMI and light activity:

2,000 kcal (baseline) + 340 kcal (second trimester) ≈ 2,340 kcal/day, so the plan targets about 2,300–2,400 kcal.

The sample day below provides about 2,330 kcal, split as about 46% carbohydrate, 20% protein and 34% fat. All three are within the Acceptable Macronutrient Distribution Ranges (45–65%, 10–35% and 20–35%). “Eating for two” does not mean doubling portions. Sarah’s extra 340 kcal is about the same as one extra snack, such as a cup of Greek yogurt with fruit and flaxseed.

Sarah’s sample one-day meal plan

Food group breakdown

The table compares Sarah’s plan with the USDA MyPlate pattern for 2,400 kcal.

Meat and beans group

Sarah needs about 6½ oz-equivalents of protein foods a day, which helps her reach the pregnancy RDA of 71 g of protein. Her plan provides about 110 g of protein once dairy and grains are counted. That is well above the minimum and fits the new Dietary Guidelines‘ emphasis on adequate protein.

• Eggs (2 oz-eq): one of the richest sources of choline. Two eggs provide almost two-thirds of her 450 mg target.
• Hummus/chickpeas (2 oz-eq): plant protein, fiber, folate and non-heme iron.
• Salmon (3 oz-eq): DHA, vitamin D and B12. Two to three servings a week meets the 8–12 oz seafood recommendation.
• Other options: lean beef (rich in heme iron) or skinless poultry cooked to a safe temperature, lentils, black beans, tofu, and nuts and seeds. Sardines, trout, tilapia, shrimp and cod are also low-mercury choices.

Fruits and vegetables

Sarah’s plan includes 3½ cups of vegetables and 2½ cups of fruit, which meets the targets of 3 cups and 2 cups. Variety matters, so Sarah should eat across the colors:

• Dark green (spinach, broccoli, leafy greens): folate, iron, calcium, vitamin K.
• Red and orange (tomato, sweet potato, mango, orange): vitamins A and C.
• Vitamin C with iron: eating vitamin C-rich foods, such as strawberries, oranges and tomato, at the same meal as iron-rich foods increases absorption of non-heme iron.
• Safety: wash all produce well and avoid raw sprouts.

Whole fruit is better than juice because it has more fiber and keeps her fuller.

Grains

The plan provides 8 oz-equivalents of grains, all of them whole grain: whole-wheat toast, a whole-wheat pita, whole-grain crackers, brown rice and popcorn. The guideline is that at least half of grains are whole. Whole grains provide fiber, B vitamins, iron, magnesium and zinc, and they release energy steadily. Sarah should also eat some enriched or fortified grains regularly, such as fortified breakfast cereal, because these add folic acid and iron.

Milk group

Sarah needs 3 cups of dairy a day: 1 cup of Greek yogurt, 1.5 oz of cheese (equal to 1 cup) and 1 cup of milk. Together with broccoli and spinach, these give her about 1,200 mg of calcium, above the 1,000 mg RDA. Dairy also supplies protein, vitamin D, iodine and choline. All milk, cheese and yogurt must be pasteurized. Fortified soy milk is a suitable alternative if she prefers.

Fluids

The adequate intake of total water in pregnancy is about 3.0 L per day, including water from food. That is roughly 10 cups (2.3 L) of fluids (IOM, 2005b). Good fluid intake supports the larger blood volume and amniotic fluid, helps prevent constipation and urinary tract infections, and reduces fatigue and headaches.

• Have a glass of water with every meal and snack (6 glasses), and sip from a water bottle between meals.
• Milk counts toward fluid intake. Water should be her main drink, as the new Dietary Guidelines recommend.
• Limit sugary drinks, and keep coffee or tea within the 200 mg caffeine limit.
• Pale yellow urine is a simple sign of good hydration. Sarah should drink more in hot weather or when she exercises.

Carbohydrate

The RDA for carbohydrate rises to 175 g/day in pregnancy, the minimum needed to fuel the brains of both the mother and the fetus (IOM, 2005a). Carbohydrate should provide 45–65% of kilocalories. Sarah’s plan provides about 270 g (≈46% of energy), mostly from complex, high-fiber sources: whole grains, sweet potato, fruit, vegetables and legumes. The plan also provides about 40 g of fiber, above the 28 g target, which helps prevent the constipation that is common in pregnancy.

• Choose complex carbohydrates over refined ones, such as brown rice instead of white rice and whole fruit instead of juice.
• Pair carbohydrate with protein or healthy fat at each meal to keep blood sugar steady, for example crackers with cheese.
• Keep added sugars under 10% of calories (under about 58 g on 2,330 kcal).

Conclusion

Sarah is a healthy woman at 15 weeks’ gestation with a singleton pregnancy, so her nutrition plan focuses on balance rather than restriction. A Balanced Plate approach provides about 2,330 kcal a day, covering her second-trimester increase of +340 kcal, and spreads her food over three meals and snacks. The plan meets every food-group target: 7 oz-eq of protein, 3½ cups of vegetables, 2½ cups of fruit, 8 oz-eq of whole grains and 3 cups of dairy. It also provides about 3 L of fluids and 270 g of mostly complex carbohydrate. With a daily prenatal vitamin, safe food handling and weight checks at each prenatal visit, this plan supports healthy fetal growth and recommended weight gain of about 1 lb per week through the rest of her pregnancy.

References

American College of Obstetricians and Gynecologists. (2010). Moderate caffeine consumption during pregnancy (Committee Opinion No. 462). Obstetrics & Gynecology, 116(2), 467–468.

American College of Obstetricians and Gynecologists. (n.d.). Nutrition during pregnancy (FAQ001). https://www.acog.org/womens-health/faqs/nutrition-during-pregnancy

Institute of Medicine. (2005a). Dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids. National Academies Press.

Institute of Medicine. (2005b). Dietary reference intakes for water, potassium, sodium, chloride, and sulfate. National Academies Press.

Institute of Medicine. (2009). Weight gain during pregnancy: Reexamining the guidelines. National Academies Press.

U.S. Department of Agriculture. (n.d.). MyPlate plan: Pregnancy and breastfeeding. https://www.myplate.gov

U.S. Department of Agriculture & U.S. Department of Health and Human Services. (2026). Dietary guidelines for Americans, 2025–2030. https://www.dietaryguidelines.gov

U.S. Food and Drug Administration & U.S. Environmental Protection Agency. (2021). Advice about eating fish: For those who might become or are pregnant or breastfeeding and children ages 1–11 years. https://www.fda.gov/food/consumers/advice-about-eating-fish