Gestational Diabetes Meal Plan: Week-by-Week Guide (Trimester 2)

Medical disclaimer: This article is for informational and educational purposes only. It does not constitute medical advice. Always follow the personalized guidance of your OB-GYN, midwife, or registered dietitian for your gestational diabetes management plan.

Managing gestational diabetes (GD) is not a one-size-fits-all task — and it certainly isn't static. Your body's insulin resistance climbs gradually across the second trimester as placental hormones peak, which means the meal plan that worked at week 13 may need recalibrating by week 24. This week-by-week guide gives you a framework for trimester 2 (weeks 13–27) that adapts to where you actually are in your pregnancy.

Whether you were just diagnosed or are looking to refine a plan that's already working, you'll find specific blood sugar targets, glycemic index values for the foods that matter most, and sample daily menus for each phase of your second trimester.

Blood Sugar Targets for Trimester 2

The 2024 American Diabetes Association Standards of Care and ACOG Practice Bulletin #190 align on the following glucose targets for women with gestational diabetes. These targets do not change week to week — they are fixed goals for the entire pregnancy:

Measurement	mg/dL	mmol/L
Fasting (morning, before eating)	≤ 95	≤ 5.3
1 hour after the start of a meal	≤ 140	≤ 7.8
2 hours after the start of a meal	≤ 120	≤ 6.7

Your provider may give you slightly different targets based on your specific history. Use the numbers above as a baseline and defer to your care team's personalized guidance.

One pattern to understand early: fasting glucose is controlled largely by what you eat in the evening, not in the morning. If your fasting number is creeping up across trimester 2, the fix often involves adjusting your bedtime snack — not skipping breakfast.

Carbohydrate Needs Week by Week

Unlike some elements of GD management that shift as pregnancy progresses, your carbohydrate distribution targets stay relatively constant across trimester 2. The Academy of Nutrition and Dietetics recommends a minimum of 175 grams of carbohydrate per day during pregnancy to support fetal brain development. For most women with GD, the practical distribution looks like this:

Meal / Snack	Carb Target	Notes
Breakfast	15–30 g	Lowest carb meal — morning cortisol increases insulin resistance
Mid-morning snack	15–20 g	Pair with protein
Lunch	30–45 g	Most flexibility here — body is typically more insulin-sensitive mid-day
Afternoon snack	15–20 g	Bridges lunch and dinner, prevents pre-dinner hunger
Dinner	30–45 g	Focus on low-GI carbs; this meal influences fasting glucose
Bedtime snack	15–20 g	Critical for fasting number — always pair carbs with protein or fat

What does shift week by week is the level of vigilance required. Most women find their numbers easiest to manage in weeks 13–16 and notice a gradual tightening of the window by weeks 24–27 as placental hormone levels rise.

Glycemic Index Reference: Second Trimester Staples

Glycemic index (GI) measures how quickly a carbohydrate food raises blood glucose compared to pure glucose (GI = 100). For GD management, foods with a GI below 55 are generally preferred. The following values are sourced from the University of Sydney Glycemic Index Database — the most comprehensive peer-reviewed GI resource available:

Food	GI Score	Category
Lentils (boiled)	32	Low
Chickpeas (boiled)	28	Low
Greek yogurt (plain)	11	Low
Apple	36	Low
Mixed berries	25–40	Low
Rolled oats (cooked)	55	Low–Medium
Sourdough bread	54	Low–Medium
Sweet potato (boiled)	63	Medium
Banana (ripe)	51	Low–Medium
Brown rice (cooked)	68	Medium
White rice (cooked)	72	High
White bread	75	High
White potato (baked)	82	High

Remember that GI scores are measured in isolation. Pairing a medium-GI food with protein, fat, or fibre lowers its effective glycemic impact in a mixed meal — this is called the glycemic load principle. A slice of sourdough toast paired with two eggs behaves very differently in your bloodstream than sourdough toast alone.

Weeks 13–16: Establishing Your Rhythm

Early second trimester is your window of opportunity. Insulin resistance is lower than it will be in weeks 25–40, nausea has typically subsided, and your appetite is returning. This is the time to establish meal-timing habits that will carry you through the rest of pregnancy.

What's Happening Nutritionally

• Human placental lactogen (hPL) is rising but not yet at peak levels — glucose management is generally more forgiving
• Caloric needs increase by approximately 340 kcal/day in the second trimester (per Institute of Medicine guidelines)
• Iron absorption increases — pairing iron-rich foods with vitamin C improves uptake
• Folic acid needs continue at 600 mcg/day through the entire pregnancy

Sample Day — Weeks 13–16

• Breakfast (30 g carbs): 2 scrambled eggs + ½ cup sautéed spinach + 1 slice sourdough toast (GI 54) + black coffee or herbal tea
• Mid-morning snack (15 g carbs): ¾ cup plain Greek yogurt (GI 11) + ½ cup blueberries
• Lunch (40 g carbs): Large salad with ½ cup chickpeas (GI 28) + grilled chicken + cucumber, cherry tomatoes, olive oil, lemon
• Afternoon snack (15 g carbs): 1 medium apple (GI 36) + 1 tablespoon almond butter
• Dinner (40 g carbs): ¾ cup lentil soup (GI 32) + baked salmon + 1 cup roasted broccoli
• Bedtime snack (15 g carbs): 2 whole grain crackers + 1 oz cheddar cheese

Focus for weeks 13–16: Establish a consistent eating schedule — meals and snacks at the same times each day. Glucose responds better to predictable meal timing than to the same total carbs eaten irregularly.

Weeks 17–20: Carb Calibration

By mid-second trimester, most women have enough blood sugar data (typically 3–4 weeks of meter readings) to start identifying their personal pattern. This is the phase for fine-tuning: which meals spike you, which foods you can handle at the high end of your carb range, and whether your bedtime snack is protecting your fasting number.

What's Happening Nutritionally

• Baby's skeletal development is accelerating — calcium needs are 1,000 mg/day (1,300 mg if you're under 19)
• Omega-3 fatty acids (DHA) become especially important for fetal brain and retinal development
• Many women report their most significant fasting glucose creep begins in this window

Calcium-Rich Low-GI Foods to Prioritize

• Plain Greek yogurt: 200 mg calcium per ¾ cup, GI 11
• Canned salmon with bones: 212 mg calcium per 3 oz serving
• Kale (cooked): 94 mg calcium per ½ cup, GI effectively 0 (non-starchy vegetable)
• Edamame: 49 mg calcium per ½ cup + 9 g protein, GI ~18

Sample Day — Weeks 17–20

• Breakfast (25 g carbs): ½ cup rolled oats (GI 55) cooked with water + 1 scoop unflavoured protein powder stirred in + cinnamon + 2 tablespoons chopped walnuts
• Mid-morning snack (15 g carbs): 1 oz cheddar + 4 whole grain crackers
• Lunch (40 g carbs): Lentil and roasted vegetable bowl — ½ cup lentils (GI 32) + roasted zucchini, red peppers, olive oil + 2 tablespoons tahini dressing
• Afternoon snack (20 g carbs): ¾ cup plain Greek yogurt + ½ cup strawberries
• Dinner (35 g carbs): Grilled chicken thigh + ½ cup sweet potato (GI 63) + large green salad with olive oil and vinegar
• Bedtime snack (15 g carbs): 1 tablespoon peanut butter + 1 small banana (half of a medium banana, ~15 g carbs, GI 51)

Identifying Your Problem Meals

Review your meter log for weeks 13–16 and ask: which meal consistently produces your highest one-hour reading? That meal is your calibration target. Common patterns:

• High breakfast readings → reduce carbs at breakfast to 15–20 g, increase protein, try savory options (eggs, avocado)
• High dinner readings → swap brown rice (GI 68) for lentils (GI 32) or cauliflower rice, reduce portion by ¼
• High fasting readings → adjust bedtime snack to always include protein + fat; try nut butter + a few crackers vs. just crackers

Weeks 21–24: The Pre-OGTT Window

Most providers schedule a second oral glucose tolerance test (OGTT) between weeks 24–28 to reassess GD management and determine whether medication is needed. The dietary habits you build in weeks 21–23 directly influence how you enter that test period — not the OGTT result itself, but your baseline glucose patterns that will guide your provider's decisions.

What's Happening Nutritionally

• Placental hormones are climbing toward their third-trimester peak — insulin resistance is meaningfully higher than in weeks 13–16
• Baby is growing rapidly; adequate protein (≥ 71 g/day per RDA) supports fetal tissue development
• Many women notice that foods they "got away with" in early trimester 2 now produce a noticeable spike

High-Protein, Low-GI Anchors for Weeks 21–24

At this stage, anchoring every meal with a substantial protein source becomes especially important:

• Grilled chicken breast: 26 g protein per 3 oz, negligible GI
• Canned tuna in water: 20 g protein per 3 oz, negligible GI
• Cottage cheese (low-fat): 14 g protein per ½ cup, GI ~10
• Hard-boiled eggs: 6 g protein each, negligible GI
• Edamame: 9 g protein per ½ cup, GI ~18

Sample Day — Weeks 21–24

• Breakfast (20 g carbs): 3-egg omelette with spinach, mushrooms, and feta cheese + ½ cup cottage cheese on the side (GI ~10)
• Mid-morning snack (15 g carbs): 12 almonds + 1 small pear (GI 38)
• Lunch (35 g carbs): Large mixed salad + 3 oz canned salmon + ½ cup chickpeas (GI 28) + avocado + lemon-olive oil dressing
• Afternoon snack (20 g carbs): Celery sticks + 2 tablespoons hummus + ½ cup baby carrots
• Dinner (35 g carbs): Beef or turkey stir-fry with broccoli, bok choy, and snap peas over ½ cup brown rice (GI 68) — note: reduce to ⅓ cup if this produces a high reading
• Bedtime snack (15 g carbs): ¾ cup plain Greek yogurt (GI 11) + 1 tablespoon chia seeds

Pre-OGTT note: Do not "diet down" in the days before your glucose tolerance test in an attempt to produce better numbers. ACOG guidelines require at least 150 g of carbohydrate per day for three days before the OGTT for the test to be valid. Restricting carbs before the test can produce a falsely abnormal result.

Weeks 25–27: Preparing for Third Trimester

By late second trimester, insulin resistance is at its second-trimester peak. Third trimester will push it further. This window is about consolidating what's working, identifying foods that need to be swapped out, and building the dietary resilience that will carry you through weeks 28–40.

What's Happening Nutritionally

• Baby's weight gain accelerates — iron needs are at their highest (27 mg/day) to support fetal iron stores built before birth
• Constipation becomes more common as the uterus compresses the bowel — high-fibre, low-GI foods serve double duty
• Some women first require insulin or metformin in this window as dietary management alone becomes insufficient

High-Fibre, Low-GI Foods for Weeks 25–27

• Lentils: 8 g fibre per ½ cup, GI 32 — among the most GD-friendly carb sources available
• Chia seeds: 5 g fibre per tablespoon, GI ~1 — sprinkle into yogurt or oats
• Avocado: 5 g fibre per ½ fruit, GI ~15, rich in monounsaturated fat
• Broccoli: 2.4 g fibre per ½ cup cooked, GI ~10 — unlimited as a non-starchy vegetable
• Split peas: 8 g fibre per ½ cup, GI 25

Sample Day — Weeks 25–27

• Breakfast (20 g carbs): 2 eggs (any style) + ¼ avocado sliced + 1 slice sourdough toast (GI 54) — keep breakfast at the lower carb end as insulin resistance peaks in the morning
• Mid-morning snack (15 g carbs): ½ cup cottage cheese (GI ~10) + ½ cup raspberries (GI ~32)
• Lunch (40 g carbs): Split pea soup (GI 25) — 1 cup — + grilled chicken breast + side of roasted asparagus
• Afternoon snack (15 g carbs): Hard-boiled egg + 10 baby carrots + 1 tablespoon hummus
• Dinner (35 g carbs): Baked cod or tilapia + ½ cup lentils (GI 32) + roasted cauliflower with olive oil and turmeric
• Bedtime snack (15–20 g carbs): 1 tablespoon peanut or almond butter + 4 whole grain crackers — protein + fat combination is critical for stabilizing overnight glucose

Meal Timing and Snack Strategy

Across all of trimester 2, meal timing is as important as food choices. Consistent spacing prevents glucose peaks and troughs that can affect both your numbers and your energy.

The 2–3 Hour Rule

Aim to eat every 2–3 hours. Longer gaps — especially skipping snacks — can trigger a rebound glucose rise as your body compensates for an extended fast. The classic pattern that produces unexpectedly high fasting numbers is skipping the bedtime snack.

Bedtime Snack: Why It Matters for Fasting Glucose

Fasting glucose (your morning reading) is partly determined by hepatic glucose output overnight — your liver releasing glucose into the bloodstream during an extended fast. A well-constructed bedtime snack suppresses this process. The formula: 15–20 g complex carbohydrate + protein + fat. Examples:

• 2 whole grain crackers + 1 oz cheese + a few walnuts
• ½ cup plain Greek yogurt + 1 tablespoon chia seeds
• 1 tablespoon peanut butter + 4 whole grain crackers
• Small bowl of lentil soup (if you had a light dinner)

Post-Meal Walking

A 10–15 minute walk after meals can reduce one-hour post-meal glucose by 10–20 mg/dL, according to a 2022 study published in Sports Medicine. This is not a replacement for dietary management but a meaningful adjunct — particularly useful after dinner when many women find their glucose most stubborn.

When to Call Your Care Team

Contact your OB, midwife, or diabetes educator if you notice any of the following during trimester 2:

• Consistent fasting readings above 100 mg/dL for 3 or more days despite adjusting your bedtime snack
• Post-meal readings above 160 mg/dL on two or more occasions
• Readings below 70 mg/dL (hypoglycemia) — particularly important if you are on insulin or medication
• Difficulty eating enough carbohydrate — inadequate carbs can cause ketosis, which is harmful to the developing baby
• Significant nausea, vomiting, or inability to keep food down — this affects your ability to manage glucose safely

GD management is a collaboration between you and your care team. Your meter data is valuable clinical information — bring it to every appointment and don't hesitate to message between visits if patterns are concerning.

Connecting Trimester 2 to the Full Journey

The work you do in weeks 13–27 is foundational. The meal-timing habits, low-GI food swaps, and bedtime snack strategies you build now will transfer directly into third trimester — when insulin resistance is highest and the stakes of blood sugar control are greatest for both you and your baby.

Breakfast is the meal that trips up most women in trimester 2, because morning cortisol makes the same carbs land higher than they would at dinner — our gestational diabetes breakfast ideas give you 20 tested morning options with carb counts. For a printable 14-day plan covering any stage of pregnancy, see our 14-Day Gestational Diabetes Meal Plan. If you would rather start with a single week, the 7-day gestational diabetes meal plan lays out seven days of meals with carb counts already worked out. If you were recently diagnosed and are still getting your footing, the First Week Survival Guide covers the initial adjustment period step by step. And when you're ready to look ahead, the Third Trimester Complete Guide picks up where this one ends.

Sources: American Diabetes Association Standards of Care in Diabetes 2024 (Diabetes Care, Vol. 47, Supplement 1) · ACOG Practice Bulletin #190: Gestational Diabetes Mellitus (2018, reaffirmed 2021) · University of Sydney Glycemic Index Database (glycemicindex.com) · Institute of Medicine, Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2005) · Buffey AJ et al., "The Acute Effects of Interrupting Prolonged Sitting Time in Adults with Standing and Light-Intensity Walking on Biomarkers of Cardiometabolic Health in Adults," Sports Medicine, 2022.