Failure to Thrive and What to do When Your Kid is Underweight

You may have heard a term in the doctor’s office called failure to thrive. Don’t worry, we’ve got some ideas for you to boost the nutrient-density of your kid’s meals. But first, let’s take a step back to understand how we track how kids grow.

How do we track kids growth? 

From birth until 18, a child’s growth is measured with a growth chart. These curves have different lines that signal a percentile. It does not matter if your child is in a high percentile or low percentile, what does matter is that your child follow’s his or her own growth curve and stays on the same percentile trajectory. 

What does it mean to follow a growth curve?

Each time you go to the pediatrician, your child will be measured (either length or height depending if he or she can stand up) and his or her weight. Each time, a health professional will ‘plot’ your child on this curve. If a child is staying at the same place or falling off that trajectory, then they are not gaining enough weight. 

How do you know if failure to thrive is happening?

There is no need to obsess over your child’s weight. Weighing is something that will happen with your pediatrician at the doctor’s office. Your doctor will tell you that your kid is not growing, some will say ‘failure to thrive’, but we have some great ideas for you get your babe back on their line. 


What to do if your kid is off his/her curve? Check your behaviors

Look at schedules

  • Try to eliminate ‘grazing’: why? Kids who graze all day tent to not eat much at mealtime. 
  • Snacks are important: Kids who don’t get offered snakcs may not be getting enough opportunities to get in calories.
  • Set a 3-2 schedule: Most kids do well with 3 main meals plus 2-3 mini-meals or snacks throughout the day. If they don’t want to eat at a meal, don’t offer an alternative, just remind them that there will be a meal or snack offered in a few hours and that the kitchen is closed until then. 
  • Stay calm: Acceptance of a new food schedule will take some time. And, this can be a very stressful concept for a parent who is concerned that their child is not gaining weight. You may not see an improvement in meals immediately and want to return to your previous feeding methods, however trust the process and give it time. Kids can be manipulative at a very early age (without meaning to) and may try to hold out for you to cave and give them something that they want. It is very important that you stand your ground and create the structure. Eventually, they will adjust to the new feeding schedule.

Assess the meal environment

  • No distractions.  Many parents find that their kid will eat more in front of a tv or ipad and end up using this as a crutch. While it may be successful in the short term, ideally you want your child to eat their meals without distraction.
  • Music may work for your kid. Some parents have better success if there is music on during mealtimes. See if it’s right for you and your family.
  • Sit down at the table and put the food on a plate.
  • Sit with your child and have a snack too: Ideally, someone will be eating meals/snacks with the child as well (either a parent, family member, or caregiver). This may not happen at every meal or snack, but should be the goal. 

Be consistent and set family rules

  • You get to write these! Write em down and follow the plan.
  • For example, everyone sits at the table until everyone is done eating. If your child finishes first, the expectation is that they continue sitting at the table until everyone is done. This obviously will not work as well for very young children, but they can work towards longer times as they age. This also may motivate a child who prioritizes play over eating to eat a little more. They are stuck sitting in the chair either way, so they may take a few more bites.

Now to the what, ideas to boost calories 

When your doctor says ‘failure to thrive’ you might think about what to eat. Here are some of our favorite tips. 

Every meal and snack should have (at a minimum) 1 high calorie food and a fruit/vegetable. Remember healthy fats are great for kids! These high calorie foods include things like nut/seed butters, avocados, full fat dairy, and animal proteins.  But this may be hard if not everyone in the family wants to pack an extra nutrient punch to their meals. No worries, we’ve got some ideas to help you make some meal tweaks.

Some ideas to add to meals or serve alone as snacks are…

6 months to 1: 

  • Egg, avocado, water-down peanut butter into a soup, meat or fish


1 and up:

  • Add an avocado to a fruit smoothie
  • Cook hot cereal with milk instead of water
  • Swap to full-fat yogurt to eat plain with fruit or blended into a smoothie
  • Nut-based granola with full fat yogurt
  • Eggs with avocado
  • Add hummus and bean dip to bread or eat with veggies


Need more help?

Our Fooblie coaches are here for you if you want to talk to a nutrition expert about failure to thrive. Seriously, they have the right mix of personal and professional experience and are here for it. Connect with a coach today!