Joan’s 2-year old boy was hungry all the time. She fed him every hour and he constantly asked for food. When I asked her what she was feeding him she revealed a diet consisting mostly of fruits and vegetables, grains, some protein and very little dietary fat. Once she filled out his diet with more fat and protein, his hunger calmed down.
Why? He was finally getting the calories and filling foods his growing body needed.
In a world where healthy eating is pressed at a very early age, parents need reminding that a “healthy” diet for kids is different than one for adults. And this especially holds true when it comes to dietary fat for children.
In part 3 in our Kids’ Nutrition Series, we’re talking about fat’s role in kids’ diets and how you can make sure your child is getting enough — and the right types — of fat.
Dietary Fat 101
Fat is an essential part of a well balanced diet. It has the advantage of carrying more energy for a smaller volume supplying twice as many calories (9 calories/gram) as protein or carbohydrates. This is why children under two require more fat — they have tiny stomachs but extraordinary energy needs. Breast milk and formula contain anywhere from 40 to 55% energy as fat.
Fat and cholesterol are “building blocks” for structural elements of cellular membranes — the brain and other neural tissues are rich in structural lipids. Essential fatty acids are instrumental in the maturing central nervous system including visual development and intelligence. And fat is necessary for the absorption and transfer of fat soluble vitamins including vitamin A, D, E and K.
Considering that the brain is still developing at 5 years of age (90% developed) and a child’s body continues to grow at all stages of development, fat is a critical part of any child’s diet.
Did you know that essential fatty acids can’t be made by the body so they need to be consumed in the diet? They include omega-6 (linoleic acid — LA) and omega 3 fatty acids (Alpha-linolenic acid — ALA) found in breast milk, formula, vegetable oils and nuts. Although longer chained omega 3s (DHA and EPA) found in fish can be made from ALA in the body, experts believe this is limited. For more on the importance of DHA/EPA for kids see this post.
Applying fat to children’s growing needs
“Fat in the diets of children is really important,” says Dr. Penny Kris-Etherton, PhD, RD, Distinguished Professor of Nutrition at The Pennsylvania State University . “Some parents think that fat is bad and end up restricting it too much.”
Take a 1989 study published in American Journal of Diseases in Children. Eight children who suffered from high cholesterol were given very low fat diets without medical supervision. Three of the children had nutritional dwarfing and five had weight loss or inadequate weight gain. The diets of children with dwarfing were the lowest in calories, fat and micronutrients.
But there’s another reason children need fat — their bodies may utilize it as a fuel source more so than adults.
According to a 2007 study led by Kris-Etherton, pre-pubescent children oxidize fat at higher rates than adults. The researchers measured metabolic rate to calculate how much fat adults and children oxidized — and calorie for calorie the children burned more.
It is hypothesized that children’s bodies oxidize fat at higher rates to support normal growth processes such as higher rates of protein synthesis.
“There are periods when kids have growth spurts,” says Kris-Etherton. “They need an adequate amount of fat which is energy-dense.”
Quick tip! If your child appears hungry all the time check the amount of fat in his or her diet. Children (and adults) on very low fat diets tend to eat more refined carbohydrates which aren’t as filling. Fat increases satiety by delaying gastric (stomach) emptying of food. Worried about weight? A recent study showed that kids who switched to low fat products ate more food to make up for it.
How much fat is enough?
Before we start attacking all who recommend low fat diets, it is important to understand that a low fat diet is not the same as no-fat diet. In general, a low fat diet is considered 30% or less of calories, which for a 2000 calorie diet is about 66g per day or less.
But like all things nutrition, people tend to go to extremes and low fat was translated to little fat. Kris-Etherton says that diets too low in fat tend to be too high in refined carbohydrates. “An unintended consequence of lowering fat has been a higher intake of calories from carbohydrates including refined carbohydrates and sugar.”
The answer is not to go to the other extreme but make sure that kids have a diet balanced with a moderate intake of fat for growth, development and meal satisfaction. The Institute of Medicine’s Acceptable Macronutrient Distribution Ranges (AMDR) are below. You can gradually lower the fat in your child’s diet as they age while making sure they have a consistent intake of fat.
The AMDR for 1-3 year olds is 30-40% of calories, 25-35% for 4-18 year olds and 20-35% for adults. For active kids that’s approximately 46g for a 3-year old, 54g for a 5-year old and 63g for a 9-year old. To give you an idea of how that translates to food a pat of butter has 4g, 1 tsp oil: 4.5g, medium egg: 5g, 1 Tbsp. peanut butter: 8g, 1/2 cup avocado 10g, 1 ounce mixed nuts: 15g, slice of cheddar cheese: 9g, 3 ounce lean ground meat: 9g, large chocolate chip cookie 9g
Saturated fats, which tend to be solid at room temperature, are found mostly in animal products such as full fat dairy, red meat and baked goods.
Trans fatty acids, also solid at room temperature, are found primarily in fried foods, commercially prepared baked goods and certain processed foods that contain partially hydrogenated vegetable oils to make fat more stable.
Unsaturated fatty acids found mostly in plants/fish include both monounsaturated and polyunsaturated fats and sources include nuts/seeds/vegetable oils/avocado and fish).
Translating advice to real life
The goal is not to count fat grams, or even to limit total fat, which has not been shown to be beneficial for health, but to include quality fat sources as a sensible (and tasty) part of meals. Here are some tips to help:
-Children under two require more fat so include full-fat dairy products such as whole milk and yogurt. After that age you can start offering lower fat dairy — a gradual decline is best.
-Provide a source of fat at each meal whether that be butter with toast at breakfast, avocado on a sandwich or an entree with added fat.
-Avoid giving children diet products that are made to be “low calorie” for adults.
-Provide unsaturated fats (plant/fish sources) more often that saturated fats (animal fats) as research shows this dietary pattern helps prevent heart disease. An example is cooking with olive over butter or using lean beef for taco night while including toppings such as guacamole. Keep trans fats, the fat most negatively linked to heart disease, to a minimum by checking labels for ingredients such as partially hydrogenated oils .
-According to the 2010 Dietary Guidelines Report, about 35% of the calories in kids’ diets come from SOFAS (solid fats and added sugars) in foods such as cakes, cookies, granola bars, soda and pizza when it really should be more like 10%. While restriction isn’t the answer, don’t allow these foods to crowd out your child’s diet. For more on how to handle such foods, see our Managing Sweets series.
While fat is the target of much controversy, it continues to be an important part of a well-balanced diet (see this article for a summary of dietary guidelines for fat). The bottom line: very low fat diets are not for kids whose bodies need the calories, nutrition and satisfaction factor on a daily basis.
How do handle fat in your child’s diet?
Lifshitz F, Moses N. Growth Failure. A complication of dietary treatment of hypercholesterolemia. Am J Dis Child. 1989: May;143(5):537-42.
Lifshitz F, Tarim O. Considerations about dietary fat restrictions for children. J Nutr. 1996; 126: 1031S-1041S.
Kostyak J, Kris-Etherton P, Bagshaw, Delany JP, Farrell PA. Relative fat oxidation is higher in children than adults. Nutrition Journal. 2007; online version
Hendrie GA, Golley RK. Changing from regular-fat to low-fat dairy foods reduces saturated fat intake but not energy intake in 4-13 year old children. Am Society for Nutrition. 2011; May;93(5):1117-27.