Carbs, Protein or Fat – How much? When? Why? [article]
Macro-nutrients – the big bad basics for energy and health
Fruit and vegetables are good but ‘carbs’ are the enemy? Some fats are good but others aren’t? Try the latest high protein diet to lose weight or take a protein supplement to add some bulk to your frame? Have you ever thought that the nutritional information (or more appropriately ‘mis’-information) circulating in the public domain is confusing and often contradictory? If it confuses you then consider what it does to the general public.
The Ministry of Health (MoH) highlights poor diet as the leading cause of death in New Zealand. In 1997 it accounted for approximately 8500 deaths compared to 5000 deaths being attributed to tobacco consumption. Considering this, is our time as fitness professionals best spent debating whether ‘carbs’ can be eaten after 3pm or actually addressing the facts relating to nutrition so we can give clear, effective guidance to our clients?
If you agree with the latter then read on and we’ll go over the big bad basics of macro-nutrients
Macro-nutrients are nutrients the body needs in relatively large quantities, they are; carbohydrates (carbs), proteins, fats, fibre and fluids. Macro-nutrients are not ‘foods’ in their own right, rather they are nutrients found in the various food groups. So advising someone to ‘cut out the carbs’ or ‘eat more protein’ isn’t specific or useful advice. The food groups that supply the macro-nutrients are; fruits and vegetables, breads and cereals, milk and milk products, lean meats (including poultry and seafood) and eggs, nuts, seeds and legumes. Oh and who could forget…alcohol.
Carbohydrates are the body’s major source of energy; they are broken down by the body to form glucose, otherwise known as ‘blood sugar’. Foods rich in carbohydrates are fruits and vegetables, which the MoH advise us to have 5+ serves of everyday for good health (3+ serves of vegetables, 2+ of fruit), breads and cereals which we should have 6+ serves of per day and legumes which we should have at least 1 serve of per day. The last survey conducted by the MoH showed that only 43% of children consumed the recommended serves of fruit and only 57% the recommended consumption of vegetables. For adults the figures were 55% and 69% respectively.
Foods that are also classified as carbohydrate include confectionary (lollies) and aerated ‘soda’ drinks (coke) which are high in excess sugar. In 2003/4 a survey of the retail trades showed that weekly household food expenditure on confectionary exceeded the expenditure on fresh fruit. The MoH recommends that 50-55% of our daily energy intake should come from carbs, however at the last survey they accounted for only 46% of the average person’s diet. So rather than ‘cutting out carbs’ a better message would be to increase the intake of fresh fruit, vegetables and wholegrain breads and cereals, and reduce the intake of confectionary and aerated soda drinks.
Fibre is a nutrient that does not actually provide us with energy. Its role is to keep the 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 helps make us feel full without actually providing us with any calories (energy). Foods high in fibre are the same foods that supply us with carbohydrates, namely fruits and vegetables, breads and cereals.
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. Fibre typically makes up the outer layers of plant foods and gives them their shape and structure. 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 cant see the seeds and grains in white bread because most of the fibre has been removed during processing and much of the nutritional value has gone.
For this reason the MoH advise people to choose wholegrain breads and cereals. But the white loafs are cheaper I hear you say…maybe so, but the wholegrain options provide sustained energy meaning you’ll actually eat less, resulting in lower calorie intake and less time spent uncomfortably on the toilet. Your choice really – healthy bowels and healthy body or cheap bread, poor performance and eventually, expensive illness.
Fat is a very concentrated source of energy, 1 gram of it provides 9 calories of energy whereas 1 gram of carbohydrate or protein provides only 4 calories. Because of this it is easy to over-consume calories when eating high fat foods. The consequences of a high fat diet include; weight gain, obesity, diabetes, cardiovascular disease and hypertension (high blood pressure).
Fat does actually serve a purpose. It is a source of energy for the body, it insulates and protects the vital organs and is required for the absorption of fat soluble vitamins (remember DEKA). Fats are classified as either saturated or unsaturated. Saturated fats are typically solid at room temperature and are known as the ‘bad fats’ because of their tendency to attach to artery walls and eventually cause blockages that can result in cardiovascular disease. Most of our saturated fat comes from animal products: meat and diary foods. Unsaturated fats are typically liquid at room temperature and come from plant foods and some seafood. These fats are known as the ‘good fats’ as they help break down the build up of saturated fats.
The MoH recommends that between 30-33% of our daily energy intake should come from fat, of which no more than 12% of the daily intake should be from saturated fat. The last surveys from the MoH showed that 35% of daily energy intake came from fat, and saturated fat was the predominant type contributing 15% of total daily energy intake. Takeaway food is typically high fat food (often saturated) and it seems we are eating more and more of it. Between 2000 and 2005 the sales revenue from takeaway food outlets increased by 67%, during this same period the percentage of household food expenditure on meals away from home increased from 10.9% to 13.5%.
Protein is an essential nutrient for the growth and repair of body tissue. We get protein from a variety of food groups including animal foods; meat, seafood, poultry, eggs and dairy products. We also get protein from some plant foods; cereals, nuts and legumes. It is recommended that protein provides 11-15% of our daily energy intake. At the last survey it was shown that our typical intake slightly exceeds this.
High protein diets are popular these days; however as many of our protein sources are also sources of fat then a high protein diet can easily become a high fat diet, with associated risks. There is no evidence to suggest that eating more protein makes you grow more, as the body tends to use what it needs and burn the rest as fuel or store it as body fat.
Approximately 70% of our body weight is water. The main purpose of drinking water is to maintain this level, or in technical speak ‘stay adequately hydrated’. To do this we need to consume about 6-8 large glasses of water everyday. There is no better source of water than tap water, it’s free and it has no calories! Other sources of fluid are not so good, most aerated ‘soda’ drinks are extremely high in sugar, and alcohol which is also high in calories, has many negative health consequences. Alcohol accounts for between 3-5% of the average daily energy intake.
So now that you know some facts about macro-nutrients, consider this;
- In 2005 advertising expenditure on chocolate, confectionary and aerated drinks exceeded $57 million in NZ, which was over 9 times the amount spent on advertising fruit and vegetables ($6 million).
- In 2005 total advertising expenditure on all fast food chains, restaurants and cafes in NZ exceeded $67 million, of which McDonalds accounted for $21million.
- Between 1997 and 2003 the prevalence of obesity in adults doubled from 9% to 20% in males and 11% to 22% in females.
The fast food, confectionary and soda drink giants certainly have no problem getting their message across. I hope you can appreciate how important it is to ensure the healthy message is not lost in the mis-information minefield. Ultimately some simple messages for clients stand out. These are:
- Increase intake of fresh fruit and vegetables to meet recommendations and choose unprocessed wholegrain sources of breads and cereals
- Reduce fat intake by choosing low fat sources of meat and diary products and low fat cooking methods such as grilling rather than frying
- Reduce or eliminate unnecessary additions of fat to our diet such as butter, margarine and mayonnaise
- Save money by reducing or eliminating unnecessary sources of poor nutrition such as confectionary, chocolate, soda drinks and alcohol
- Drink a glass or two of water with every meal to provide a sense of fullness without extra calories
For more information on macronutrients and their intakes in NZ follow the hyperlink to these articles;
Note: National nutrition surveys are conducted approximately every 10 years, the last major one was in 1997. The MoH is conducting another survey currently (2008/9) the results of which are due in 2011.