Fueling fast kids

Non-stop kids need good fuel to keep them going ...
Non-stop kids need good fuel to keep them going ... Photo: Getty Images

We all hear the messages about the importance of kids eating healthy food – with a great emphasis on eating fresh and lowering the intake of processed foods. But how does this message apply to a child’s energy needs? Don’t kids just always seem ready to jump around and burn up the seemingly endless supply of energy they have regardless of whether they ate white toast and jam or a home-cooked organic meal?

Well, yes, maybe for a little while, but, in the long-term, just like other consequences of eating the ‘wrong’ foods - such as obesity and behavioural problem - there is an impact on the child’s body’s energy production and distribution.

The oft-quoted analogy of filling up your car with fuel to give it the ability to run applies here too. The greater the quality of fuel, the ‘cleaner’ the energy that is produced and the longer the engine will run without too many problems.

Carbohydrates give the human body the best source of fuel. The other two food groups important for energy production are fats and protein. Food is broken down in the stomach with the assistance of stomach acids into simple sugars such as glucose. This glucose is transported around the body by the blood, where each cell will ‘burn’ it, with the assistance of oxygen, vitamins and minerals to produce energy.

Annalies Corse, a medical scientist and nutritionist says that carbohydrates are the easiest to process for the body.

“Simple carbohydrates (sugars) are absorbed very quickly [into the bloodstream] (within a couple of minutes). Fats, proteins and more complex sugars take longer, but absorption of these can start about 20 minutes after eating (especially if you chew well),” she says.

Generally, almost all the carbohydrates consumed will be used to make energy, especially if the child is active, says Corse.

“Protein will be used to build muscles, organs, bones and build health. Both fats and carbohydrates that are not needed immediately for energy are stored away. When kids go through a growth spurt, these stored fats and carbohydrates can now supply the energy needed for growth/development.”

However, eating large quantities of fatty foods can cause the child to feel sluggish especially if they are not active, thus resulting in it being stored and contributing to body fat.


In addition, eating certain foods with a higher glycaemic index (the effect of carbohydrate-containing foods on the blood sugar levels over a period of time) can result in rapidly rising blood sugar levels (and an energy boost). The body counteracts this by releasing insulin which also triggers the release of sleep-inducing chemicals, causing lethargy and a downward slump – the typical yo-yo effect. These foods don’t just include the sugar-laden culprits like cakes or lollies, they can also include seemingly ‘healthier’ options like potatoes or wholemeal bread.

Furthermore, the effect of consuming highly processed foods does not impact a child’s energy levels only in the short term. Jacinta Harding, a nutritionist specializing in kids’ health says we are now seeing the second or third generation of families consuming highly processed foods, contributing to allergies, intolerances and deficiencies.

Deficiencies can result in longer-lasting fatigue and restlessness, as is the case with iron deficiency or anaemia, says Corse.

In terms of fuel for the body, highly processed foods deliver a lot of energy but virtually no vitamins or minerals, she explains. “Some of these micronutrients are essential for the chemical breakdown of food to make energy, especially B2, B3, B5, Calcium, Magnesium and Biotin. Kids can actually use up these B vitamins and minerals really fast if they exist on a processed food diet, to the point where they use up so many that they become deficient in these vitamins and minerals,” she says.

So, what’s the best way to ensure children fill up on foods that sustain their energy levels efficiently for both the short and long terms?

Go back to the basics of good quality protein, vegetables and fruit, says Harding. “Include some good quality oils such as those found in nuts, avocado, seeds and olive oil, but stay clear of processed foods. As they say, if you look at the label [of a product] and you cannot grow all the ingredients, then it is not a food.”

“The best way for kids to meet their energy needs is to eat real food and eat regular meals that are as nutritious as possible. Kids’ energy needs range from 3 to 8 MJ/day (mega joules per day) depending on their age, weight and gender. It is very important to make sure that children are eating plenty of carbohydrates and fats. Both drive energy production, which not only allows kids to be active, but provides them with the massive amounts of energy they need to grow,” says Corse.

But, be selective with the carbohydrates you feed your children and opt for vegetables, ripe fruits, legumes and certain grains, she advises.

For further information on how foods are converted to energy and to choose the best options, visit Fuel for Life.

Sources include Dairy Australia, Better Health Channel, Raising Children and Scientific American