WHY SIZE MATTERS: PART 1 – THE RESEARCH
The American Academy of Pediatrics recently published a new study about bottle size and the suspected weight change effects it has on an exclusively formula fed babies. The study found that:
“Using a large bottle (greater than 6oz) in early infancy independently contributed to greater weight gain and change in WLZ at the 6-month visit.”
Essentially, this means that if parents used bottles that were larger than 6oz, their babies were larger on the Weight – Length scale (WLZ, found on the WHO growth charts) than those who used a smaller bottle size (less than 6oz). Highlighting this fact for parents is an important step in understanding bottle feeding, and in learning proper techniques to help babe get enough energy (but not too much) from their bottle.
In this three part series I will help clarify some of the outcomes of this study, explore ways to keep baby’s satiety cues intact while exclusively bottle feeding and finally relate it all back to breastfeeding!
Why does size matter?
Another study published in 2000 showed that:
“Larger portions led to greater energy intake regardless of serving method and subject characteristics. Portion size is a modifiable determinant of energy intake that should be addressed in connection with the prevention and treatment of obesity.”
Over the years we have heard from dieticians to control portion sizes through smaller plates and smaller cups when we eat. This will help control how much we are eating and help us control the amount of energy that we are receiving in a day.
Now experts are saying that we need to do the same with our exclusively formula fed babies. In using bottles that are more than 6oz, we tend to give our babes too much energy throughout the day from their food. Formula fed babies need to drink more and more as they get older and once they reach six months of age, they can be taking in anywhere from 6-8oz at a feeding. Therefore it would seem fine to go ahead and use a larger bottle to make things more efficient. Unfortunately, there are consequences with this.
When we put the exact or maximum amount our babes should be eating at every feeding in their bottle, we aren’t taking into account any variance in hunger from feed-to-feed that our babe may be experiencing.
If babe has left 0.5oz or 15 mls at the end of a feed, most parents (from my experience) say they will try to get babe to take that last little bit through a variety of tricks including twisting the bottle, burping babe and trying again, or just waiting a few minutes. We try to get them to ‘finish the bottle’ so we can fill them up until the next feed. This article tells us that babes will let us know when they are full, so go ahead and fill them up! But if they are consistently given a bit more than they need, then babe’s “full” cues can be altered over time. If we change the way a babe ‘feels’ full this early on in life, how will the affect those cues when they are toddlers, teenagers and adults? For this reason the study makes a point that perhaps this needs to be looked into further as a way to prevent future obesity.
Here are some questions to think about when you are eating throughout the day:
1. Do you feel like eating the same amount every time you eat or do you choose how much you eat depending on how hungry you are?
2. If you are hungry 30 minutes later, do you make yourself hold off to the next meal, or do you go ahead and eat?
3. If you eat again, do you only have a snack or do you give yourself the exact same portion size you ate just 30 minutes before?
The answers should depend on how healthy your relationship with food is.
As adults decide when/where/what/how food happens. We get to make all those decisions for ourselves, and as this study suggests, we are making them for our babies as well. Everything you read about formula feeding talks about amounts and schedules and so, as caring parents, we follow the suggestions. According to the instructions, babe needs to feed “this many ounces” every “this many hours” with little to no word on variance between feeds nor letting the babe have an active role portion size. We are unknowingly giving our babes too much because we are filling those bottles either to the top or to the max amount babe will eat every time.
Size DOES matter when it comes to the bottles we are using to feed our babes. It matters to their weight gain at 6 months, and for perhaps a lifetime. Using larger bottles means that parents tend to give larger volumes of formula at each feed, resulting in a bigger weight gain for these babes.
In Part 2: What can we do? We will look into not just reducing the bottle size, but the portion size and look at different ways to bottle-feed both or formula fed and breastfed babies to better respect their feeding cues and satiety cues.