Weight Gain Strategies for Kids: What to Do When Your Child is Underweight

Dianna Scott
May 12
3 min read

As a parent, it’s natural to worry when your child seems smaller than their peers or isn't gaining weight as expected. Maybe they have a tiny appetite, skip meals, or are stuck wearing the same size clothes for too long. These are common concerns—and they often point to growth concerns in toddlers and kids.

Being underweight doesn’t always mean there’s a medical issue, but it can signal that your child isn’t getting the energy or nutrients they need for healthy development. The good news? There are proven nutrition strategies that can help support safe and steady weight gain for kids.

In this post, we’ll walk through what being underweight really means, and share practical, food-based strategies you can use at home to help your child grow strong and thrive.

What Causes Low Weight in Children?

First, it’s important to understand what “underweight” means. In children, it’s often flagged when:

Weight falls below the 3rd percentile on a growth chart
There’s a noticeable drop in weight percentile over time
They’re not gaining as expected for their age and height

There are many possible reasons for low weight in kids, including:

Small appetite or picky eating
High energy needs (due to rapid growth, activity, or medical conditions)
Illness, digestive issues, or poor nutrient absorption
Stress or behavioural feeding challenges

While genetics can also play a role, chronic low weight should be evaluated—and with the right approach, nutrition can help make a meaningful difference.

High-Calorie, Nutrient-Rich Strategies for Weight Gain

Here are effective and parent-friendly ways to support healthy weight gain for your child:

Offer Frequent Eating Opportunities
- Aim for 3 meals and 2–3 snacks per day. Young children need regular fuel to grow. However, it is important to avoid grazing throughout the day and focus on scheduled meal and snack times.
Add Healthy Calories Without More Volume
- Stir nut butters into oatmeal, blend avocado into smoothies, or sprinkle shredded cheese on eggs or pasta.
- Add oils (olive, vegetable, or margarine) to cooked veggies, soups, or grains.
- Choose whole fat dairy options
Prioritize Nutrient-Dense Foods
- Focus on whole milk, Greek yogurt, eggs, legumes, and fatty fish like salmon.
- Limit low-calorie “fillers” like crackers, puff snacks, or juice.
Make Smoothies or Milkshakes
- Blend full-fat milk with banana, nut butter, Greek yogurt, and oats for a high-calorie, kid-approved snack.
Avoid Pressure at the Table
- Mealtime stress can reduce intake. Keep it calm, and let your child decide how much to eat from the foods you offer.
Consider a Pediatric Nutrition Consultation
- A dietitian can develop a personalized weight gain for kids plan that’s realistic, safe, and tailored to your child’s preferences.

Common Questions About Weight Gain in Kids

What are the best high-calorie foods for children?

Some great choices include whole milk dairy products, nut butters, avocado, eggs, hummus, granola, and healthy oils like olive or other vegetable oils.

Is it okay to offer treats to help with weight gain?

Occasional treats are fine, but the goal is nutrient-rich calories. Focus on whole foods that also offer protein, fats, vitamins, and minerals.

My child is active and healthy—should I still be concerned?

If your child is consistently underweight or not growing along their curve, it’s worth checking in with your doctor or dietitian to rule out underlying issues.

Support Your Child’s Growth With Confidence

Helping a child gain weight can feel like a big challenge—but you’re not alone. With regular, high-calorie meals and the right support, your child can gain weight in a healthy, sustainable way.

🍽️ Need help building a personalized meal plan? Book a consultation with Sprout & Shine Nutrition. Our pediatric dietitian will work with you to create a family-friendly strategy that fits your child’s needs—and eases your concerns at the table.