In the galaxy of food, is sugar on the side of darkness or light? Amanda Cossey takes her Lightsabre of Science to the subject.
‘Sugar is toxic.’ It has a sexy ring to it, doesn’t it? Much more appealing than ‘eat more veggies or less junk food.’ Sugar is the most recent component of our diet under fire – fat is back and sugar is out. The anti-sugar push is driven by the belief that obesity and the many lifestyle diseases plaguing us are caused by sugar. The food industry is happily reinforcing this idea, creating sugar-free products with ingredient lists as long as your arm to replace your sugar-containing bananas and potatoes. The truth is that some people do eat too much sugar. The World Health Organization recommends approximately 55g of free sugar* per day (*free sugar = sugar added to food and drink as well as naturally occurring in honey, syrup and juices. It doesn’t include naturally occurring sugar in milk, fruit and vegetables). If you consider that a 600mL Coke contains 63.6g sugar, it is easy to see how you can over do it. But sugar is just one component in a bigger picture. Is sugar actually toxic? Is the ‘sugar free’ version really better? And what should we be focusing on to have a truly clean, more balanced diet?
So we can understand our food a little better, let’s start with the science of sugar. From an energy point of view, sugars (saccharides) and starches provide 16-17kJ/gram, the same as protein. Sugars, there are a few, are the building blocks of carbohydrates and have different names depending on their construction. Structurally, these carbohydrates can be classified into two groups, simple and complex. The simplest sugars, monosaccharides, are the single-sugar molecules – glucose, fructose and galactose. Disaccharides are double sugar molecules, where two of the single-sugar molecules are joined together to make sucrose (glucose + fructose), maltose (glucose + glucose) and lactose (glucose + galactose). Complex carbohydrates, on the other hand are called polysaccharides, which are long chains of monosaccharides.
We get these sugars and starches from the foods and drinks we consume. Some, like lactose in milk and fructose in fruit, occur naturally. These are good sugars. Other sugars, for example, sucrose, are added to our food. Each group of sugars acts slightly differently when in our bodies depending on their structure and what food it has come from. The speed of digestion and absorption are determined by the structure of the sugar, the enzymes released by the body when we eat it and what other nutrients are eaten with it.
Digestion begins in our mouths. An enzyme in our saliva (salivary amylase) begins breaking down starch molecules into individual glucose molecules. This process continues in your small intestine where the sugar molecules are broken down by specific enzymes to their single sugars (fructose, galactose and mostly glucose), which are then absorbed into the bloodstream. Glucose is the primary fuel for the cells in our bodies, with our brain using around 60% of our glucose supply. Cells throughout our bodies use the rest. Glucose is particularly important for prolonged continuous or high-intensity exercise.
Our bodies also have stores of carbohydrate (in the form of glycogen) in our liver and muscles that we can draw upon during exercise. We generally store up to 500g, with fitter and more trained athletes able to store more. If your stores can’t meet your training and climbing fuel needs, your training or climbing performance will suffer, your fatigue levels will increase and you can compromise your immune system. Therefore it is important, as an athlete, to make sure you eat enough carbohydrate around your training sessions and throughout your climbing day to help meet your fuel needs. For these reasons, we need to plan carbohydrate intake around key training sessions and make sure we have some with each meal. Going sugar free may actually hinder the gains you are looking for.
So is sugar toxic? No, it’s not. If you have an excess, it’s potentially harmful in the same way too much campusing, carrots, water or even oxygen are. A key problem with the ‘sugar is toxic’ message is that it doesn’t discriminate between Coca Cola, Weetbix and an apple, all of which contain sugar but are very different foods. The ABS (Australian Bureau of Statistics) released data on the average Australian diet just this month. Two stats really stand out. First, only 4% of us actually eat enough veggies and, secondly, on average, 35% of what we eat each day is junk food (pastries, cakes, alcohol, soft drink, lollies and chocolate). To really make a difference to our health, to have the ‘clean diet’ many aspire to eat, we need to focus on what actually goes into our mouths rather than what isn’t.
While we are fixated on cutting sugar out, we are missing the bigger picture and therefore the opportunity to actually eat better. If we cut out all sugar-containing foods or replace them with ‘sugar free’ options, with little discrimination or understanding, we are cutting out a bunch of foods that are actually quite good to eat and keeping in a bunch of foods that are as bad as the sugar-laden ones. Sugar free doesn’t automatically equal healthy and a sugar-free cake is still a cake.
Tips for Cleaner Eating
- Aim for a minimum of two to three cups of vegetables/salad every day.
- Sugar isn’t toxic, but a lot of processed food can be. Focus on cutting out as many packets and jars as possible.
- Cut back on your junk food and check the ingredients lists on your ‘sugar free’ products.
- Aim for a minimum of 25g fibre/day (from fruit, vegetables, nuts, seeds, grains and legumes).
- Aim for low GI (glycemic index) carbohydrates most of the time. They will help maintain good blood-sugar control, keep you feeling full for longer and help maintain better body composition. The higher GI carbohydrates can be used before and after training on climbing days where you need a quick hit of energy.
- When you are reading a nutritional panel in terms of sugar and carbohydrate, take note of the following. Total carbohydrate includes both sugars and starches in food. Use the total carbohydrate figure in the ‘per serving’ column to determine how much carbohydrate you are eating in one meal or per serve. Sugars: this tells you how much of the total carbohydrate is sugar. This includes ‘added sugar’ as well as naturally occurring sugars from fruit (fructose) and milk (lactose), if they are ingredients in the food. Remember it is total carbohydrate that affects blood glucose levels, not just sugar. The amount of sugar in a food is not a very useful guide to decide whether it is a healthy food.