Carbohydrates and Dietary Fibre

Firstly – what are macronutrients?

Nutrients needed in relatively large quantities are called macronutrients.  Macronutrients include; carbohydrates and dietary fibre, fats, proteins, and fluids.  Micronutrients on the other hand are nutrients that are needed in small quantities, these include; vitamins and minerals.

It is important to make the distinction that macro and micronutrients are not actually foods or food groups per se; rather they are the nutrients that are found within the foods and food groups. 

The macronutrient food groups are; fruits and vegetables, breads and cereals, dairy products and meat and meat alternatives.

All too frequently we hear stupid statements being made such as ‘Don’t eat carbohydrates after 3pm’.  Now if this statement were to actually mean something for one of your personal training clients it needs to be specific, and would be better expressed as ‘Don’t eat any foods containing carbohydrates after 3pm’. 

With this refined statement the stupidity of it becomes more obvious; for a client this effectively means don’t eat any of the following foods; all fruits, vegetables, breads, cereals, nuts, seeds or legumes after 3pm as these are the foods that contain carbohydrates. 

This would essentially leave your poor personal training clients with nothing but meat and dairy foods to eat, which unfortunately are the food sources that contribute most to high saturated fat intakes, obesity, heart disease, diabetes and premature death – hardly ideal guidance for someone you’re trying to help to improve their health!

Ambiguous, confusing and misleading statements such as the ‘don’t eat carb’s after X hour’ should never be made or accepted by personal trainers.  These statements simply highlight people with a poor understanding of nutrition and a poor grasp of the reality that the clients who look to us for guidance need to be provided with clear, specific and accurate information.

So to cut a long story short – always talk in a language your clients understand.  When it comes to nutrition your clients are much more likely to understand you when you talk about foods and food groups rather than macro and micronutrients!  That being said, as a personal trainer you must know the fundamentals of all of these nutrients, so let’s look initially at carbohydrates and dietary fibre…

Carbohydrates and Dietary Fibre

Carbohydrates usually provide the largest single source of energy in any diet.  When consumed, carbohydrates are broken down by the body to form glucose (known as ‘blood sugar’, or ‘blood glucose’), which is an easily available form of energy that fuels the millions of reactions and functions occurring in the body every second of the day.  Some of the bodies systems, (e.g. the nervous system) and any type of exercise that is high intensity rely exclusively on energy derived from carbohydrates.

As previously mentioned the foods that are high in carbohydrate include; all fruits and vegetables, breads and cereal foods (including pasta and rice), and nuts, seeds and legumes.

Foods that are also high in carbohydrate include all confectionary (sweets) and carbonated soda or ‘fizzy’ drinks which are very high in added sugar that we simply do not need.  It is worth noting that carbohydrates supply four calories of energy per gram as opposed to fat which provides nine calories per gram (protein also provides 4 calories per gram).  So carbohydrate foods have less than half the calorie content of high fat foods.

The national nutritional guidelines for most western countries recommend that between 55-65% of all of the energy we consume should come from carbohydrates.  And specifically, that people should consume at least (often more than) 5 servings of fruit and vegetables per day, and 6 servings of wholegrain bread and cereal foods per day. 

Carbohydrates – Are we eating too much or not enough?

As carbohydrates provide the largest source for the production of energy without enough of them we fatigue quickly, lose concentration and can feel dizzy or faint.  Because high carbohydrate foods also carry a lot of vitamins and minerals if our intake of these foods is deficient then we are vulnerable to a greater range of illnesses through micronutrient deficiency. 

However an excess total energy intake from carbohydrate (usually in the form of added sugars, confectionary and fizzy drinks) can contribute to weight gain and obesity.  But because carbohydrates supply less than half the amount of calories as the equivalent quantity of fat it is very hard to have too much (if they are the right type of ‘good’ carbohydrates that is…)

Information from across the western world shows that most adults fail (often miserably) to consume the minimum recommended amounts of fruit, vegetables and wholegrain breads and cereals.  Yet at the same time the soft drink and confectionary giants are running extremely profitable businesses selling…sugar!  You see there really is a case of ‘good carbs vs. bad carbs’ and it appears that the bad carbs are winning in far too many cases.  Unfortunately many health and fitness professionals aren’t helping the situation by not being clear about what people should be eating more or less of.

Because fat is such an energy dense nutrient and it figures so prominently in the western world a much greater percentage of energy comes from fat then is recommended.  Consequently it appears that not enough of our energy comes from carbohydrate (remember that 55-65% of our energy intake is recommended to come from carbohydrates…most research shows that carbohydrate generally  accounts for less than 50% of total energy intake).

We need to offset this information however with the reality the people in the western world are simply consuming far too many calories as evidenced by the prevalence of overweight and obesity in our societies.

So when it comes down to providing clear and specific guidance to help what is likely to be the majority of your personal training clients, that guidance should revolve around;

• Reducing total caloric intake primarily by reducing fat intake and reducing or eliminating foods and drinks high in added sugar

• Reducing the intake of highly processed carbohydrate foods such as white bread (we’ll discuss this more shortly…)

• Offset these reductions by increasing the intake of fresh fruit and vegetables in particular, as well as choosing wholegrain breads and cereals as alternatives to heavily processed breads and cereals

Dietary fibre

Most of the recommended foods that are high in carbohydrate are also high in dietary fibre, namely wholegrain breads and cereals, many fruits and vegetables, and legumes such as peas, beans and lentils. 

Dietary fibre is usually found in the walls of plant foods where it helps to provide structure and support to the plant.  Dietary fibre does not actually provide us with any calories, its role is to keep the human digestive system healthy and protect us from constipation, bowel cancer, irritable bowel syndrome and haemorrhoids amongst other things.  It does this by passing directly through us without being digested; it keeps our ‘bowel movements’ regular and helps make us feel full without actually providing us with any calories. 

A problem with much of today’s food is that it is heavily processed, i.e. a lot happens to it in the factory before we consume it.  During the processing of food much of the fibre is removed.  You can see this when you look at a loaf of white bread in comparison to wholegrain bread.  You can’t see the seeds and grains in white bread because most of the fibre that gave those seeds and grains their ‘form’ has been removed during processing and consequently much of the nutritional value has gone.

This is why most national nutrition guidelines advise people to choose wholegrain breads and cereals.  The fibre rich wholegrain options slow the process of digestion thus providing sustained energy over a longer time meaning people with lots of fibre in their diets will likely eat less and have much healthier bowels – which is good for them and the people around them. 

When we consume a lot of sugar and highly processed, low fibre foods these foods are absorbed rapidly into our blood causing rapid increases in our blood sugar levels.  If this energy isn’t used it is stored as glycogen.  If the body’s glycogen stores are full then it will be converted into and stored as body fat.

So by encouraging your personal training clients to choose high fibre wholegrain breads and cereals and to eat more fresh fruit and vegetables not only will you help them control their bodyweight but you’ll help them regulate their blood sugar levels (and protect against diabetes), as well as protect them from suffering from irritable bowel syndrome, constipation, bowel discomfort and eventually bowel cancer.  Pretty good really for you and your clients!