Throughout this site you will find various references to the ‘glycaemic index’ or ‘GI’ – essentially a measure of the speed an extent to which a food disrupts blood sugar levels. Relatively high GI foods will tend to cause surges in the hormone insulin which, in time, can predispose to a range of ill effects including weight gain (particularly around the mid-riff), type 2 diabetes and heart disease.
In the short term, there is the potential for gluts of insulin to drive blood sugar levels down to sub-normal levels, which can have effects on wellbeing. Not uncommonly, eating high GI foods induces fatigue 2-4 hours later. In fact, this is probably a major factor in the mid-late afternoon slump some people experience (particularly if lunch constituted a sandwich!).
Another element of human performance that can suffer as a result of blood sugar lows is brain function. The brain may only make up about 2-3 per cent of body weight, but it is believe to use more than half of the sugar in the bloodstream at rest. What this means is the brain is quite a sugar-dependent organ, and if it doesn’t get enough of this fuel, it can be prone to exhibiting symptoms such as mood swings, low mood and irritability, as well problems with memory and concentration.
So, could it be that eating low GI (relatively slow sugar-releasing) foods helps memory and concentration?
This concept was tested recently in a study published in the journal Appetite. Researchers at the University of Northumbria in the UK fed children aged 6-11 years either All Bran (GI 42) or Coco Pops (GI 77) on two consecutive days. The attention and memory of these children was tested before the breakfast, and then tested immediately after breakfast, and then again one and two hours after breakfast.
Perhaps not surprisingly, eating a low GI cereal led to generally better maintained ‘cognitive performance’ with regard to attention and memory during the morning than eating a high GI cereal.
Below, I have added a couple of previous articles, one of which explores the potential benefits of eating breakfast in more depth. The other offers some suggestions for what I believe to be relatively healthy breakfast options for kids (or adults for that matter).
Ingwersen J, et al. A low glycaemic index breakfast cereal preferentially prevents children’s cognitive performance from declining throughout the morning.
Appetite. 2007 49(1):240-4.
The importance of eating breakfast – 15 September 2002
When I was growing up, I remember my father making sure that me and my four siblings got a decent breakfast inside us before leaving the house for school. Like a lot of parents, my Dad believed that eating breakfast helped to set little bodies up for the day. A compliant child, I spent my formative years munching my way through bowlfuls of Shredded Wheat, Alpen and Reddy Brek, convinced that this must be doing me some good. These days, I’m far less keen to swallow conventional nutritional wisdom without thinking, and recently resolved to discover if there is any real evidence for the benefits of eating breakfast in kids. As it happens, research suggests that having breakfast helps feed the brain, and can actually boost a child’s learning at school. It appears that taking my father’s advice and not forgoing my morning meal may have turned out to be a smart move after all.
The brain needs fuel to function properly, and gets the bulk of its requirements in this respect directly from food. The brain’s principle fuel is sugar, and maintaining adequate levels of this most basic energy source in the bloodstream is critical for normal mental function. Many children may go 10 or more hours between their last meal of the day and the next morning. With such a long gap between fuel stops, it is not uncommon for blood sugar levels to drop to sub-normal levels overnight. This can cause a child to be tired and grumpy in the morning, and can certainly take the edge off even the sharpest of minds.
One important benefit of eating breakfast is that it supplies ready fuel to the brain. A number of studies have found that when children skip the first meal of the day, memory, verbal fluency, and mathematical dexterity may suffer. By restoring blood sugar levels after the overnight fast, eating breakfast helps ensure a child has a productive morning in the classroom. However, regular breakfasting might have important long term benefits as well. Breakfast may also supply important nutrients to a growing body and mind, thereby improving a child’s general nutritional status. This is likely to reap dividend in terms of physical well-being and mental functioning on a global level too.
To date, there have been three studies that have examined the impact of eating breakfast on children’s behaviour and learning. Interestingly, these studies found that children who did not skip breakfast were less likely to skip school too. So, the evidence suggests that eating breakfast not only helps learning, but may increase the amount of learning a child is subjected to too. It comes as no surprise, therefore, that all three of the studies that have been conducted in this area found that eating breakfast is associated with better performance in a variety of scholastic tests.
Getting down to the specifics of what to feed a child in the morning, my preference would be a bowl of porridge or oat-based muesli. A hard-boiled or poached egg with a slice of proper wholemeal toast is another decent option. In addition, if a child is happy to have a piece or two of fruit, or even some freshly squeezed fruit juice, then so much the better. Getting something healthy into a child early on in the day may well enhance the chances of stuff going in up top too.
Kid’s breakfast cereals are notoriously rubbishy – what can you feed them in the morning that really sets them up for the day? – 18 September 2005
Recently, I have noticed a spate of adverts which suggest that eating a bowlful of cereal in the morning can help kids’ concentration. The Advertising Standards Authority (ASA) recently received several complaints about one such advert claiming that ‘Studies show a breakfast like Shreddies helps give kids the mental energy they need to stay involved at school’. Shreddies’ manufacturer, Cereal Partners UK, were only able to offer one small study which tested the effects of its cereal in this respect. The ASA adjudged that the advert made potentially misleading claims for the supposed brain boosting effects of Shreddies on children’s performance in the classroom, and duly wrapped its manufacturer across the knuckles by banning the advert in its original form.
In their defence, Cereal Partners UK cited other evidence which appeared to support the notion that eating Shreddies for breakfast can help kids’ concentration. However, most of these studies compared the effects of eating some sort of breakfast with eating nothing at all. Because breakfast eating will help refuel the brain after the overnight fast, it comes as no surprise that consuming something rather than nothing in the morning turns out to be better where concentration is concerned. However, I have considerable reservations about the oft-touted notion that kids’ cereals are the healthiest fare with which to start the day.
One major downside to most breakfast cereals is the fact that they give relatively brisk and substantial release of sugar into the bloodstream. Such sugar surges will tend to cause excesses of the sugar-lowering hormone insulin, which may drive blood sugar levels to subnormal levels later one. In my experience, such a stalling of sugar delivery to the brain may precipitate problems such as poor concentration, and undesirable changes in mood and behaviour in the late morning. And in the long term, gluts of insulin in the system will predispose young bodies to both weight gain and type 2 diabetes. The heavily salted nature of many breakfast cereals is another reason for them to be left on the supermarket shelf.
Whilst I am a hearty advocate of some form of breakfast, I do think it makes sense that this comes in the form of something truly wholesome that will also gives a relatively slow and sustained release of sugar into the bloodstream. An unsweetened oat-based muesli containing highly nutritious foods such as nuts, seeds and dried fruit will tend to fit the bill in this respect.
However, not all children are happy to eat much in the morning, and may therefore do better on a liquid start to the day in the form of a smoothie. Nutrient-packed berries such as strawberries, raspberries or blueberries make ideal ingredients here. The addition of natural yoghurt to a fruit-based smoothie may improve its texture and flavour, and will also help to ensure this drink gives a sustained release of sugar to the brain throughout the morning. Nutritious, slow-sugar releasing breakfasts would be my choice for giving kids a head start in the morning.