Behind the Hype: Carbohydrates
In a nutshell
- Carbohydrates are essential for good health because they provide the main source of energy for the body and brain.
- Eat carbohydrates with a higher fibre content, such as wholegrain breads, rolled oats or wheat biscuits rather than lower fibre carbohydrates, such as white bread or puffed wheat.
- Eat at least five servings of fruits and vegetables every day.
- Avoid energy-dense foods that are high in sugar and fat such as soft drinks, lollies, cakes, biscuits and sweetened breakfast cereals.
- All fruit juices and fruit drinks contain lots of sugar – even those labelled as pure fruit juice. Restrict consumption of these beverages.
Why is this an issue?
Popular media suggests we should cut carbohydrates from our diets. This opinion is often based on suggestions that eating carbohydrates provides excess energy to the diet and contributes to weight gain.
What are carbohydrates?
Carbohydrates are organic compounds naturally occurring in many foods, including fruits, vegetables, breads, cereals, pasta and rice. Carbohydrates are classified according to their chemical forms. Polysaccharides (previously classified as complex carbohydrates) include starch and fibre and are found in fruits, vegetables and wholegrain cereals.
Sugars (previously classified as simple carbohydrates) occur naturally in foods such as fruits, honey and milk. Fruits are also a source of vitamins so should be eaten every day. The word ‘sugar’ usually refers to refined table sugar (sucrose), but there are many other types of sugar eg, lactose, fructose, maltose and glucose. Sugars can be added to foods in many other forms, such as molasses, glucose, dextrose, brown sugar, fruit purees, honey, golden syrup, palm sugar or corn syrup. Look out for these on food labels.
Dietary guidelines do not recommend limiting sugars such as those in fruit and milk as these foods are not considered to have adverse health outcomes and provide other beneficial vitamins and nutrients. However, added sugars (ie, added by the cook, manufacturer or consumer) plus sugars concentrated in honey, syrups and fruit juices should be limited.
Is it important to eat carbohydrates?
Carbohydrates are essential for good health because they provide the main source of energy for the body, particularly the brain as it needs glucose from carbohydrates to function.
Foods that contain polysaccharides usually contain other beneficial nutrients, such as vitamins, minerals and antioxidants. Avoiding these foods puts you at risk of nutrient deficiencies. However, because carbohydrates provide energy they can contribute to weight gain when too much is eaten.
Advice for pregnant women
It is especially important that pregnant women eat plenty of fruits and leafy green vegetables, which are the best food source of folate, a vitamin essential for the development of healthy babies.
Women planning a pregnancy should also take a daily folic acid tablet for at least four weeks before they become pregnant through to week 12 of their pregnancy, to reduce the risk of neural tube defects. More information on folic acid during pregnancy is available from: www.health.govt.nz/our-work/life-stages/maternity-services/supplement-tablet-take-when-pregnant-or-breastfeeding
Always wash and dry fresh fruits and vegetables before eating. More information on food safety for pregnant women is available from: www.foodsmart.govt.nz/information-for/pregnant-women
Eat wholegrain cereals to help prevent constipation. More information on healthy eating for pregnant women is available from: www.health.govt.nz/our-work/preventative-health-wellness/nutrition/food-and-nutrition-guidelines
What about carbohydrates and weight?
To lose weight, you need to use more energy than you eat from foods and beverages (this creates an energy deficit). Therefore, you need to increase the amount of energy used through being physically active and/or eat less.
Long term studies of low-carbohydrate, high-fat, or high-protein diets have shown weight loss can occur. However, this weight loss is due to a sustained energy deficit rather than to lower or higher amounts of protein, fat or carbohydrate. There is no long-term evidence that any particular diet is better than another for weight loss.
The key to successful weight loss and weight management is long-term sustainable lifestyle change. Highly restrictive diets are not sustainable long term and, therefore, weight loss is not maintained.
The best ways to lose weight and maintain a healthy weight are to:
- develop healthy eating habits such as reducing portion sizes, eating plenty of low-energy vegetables (such as leafy greens, carrots, etc), eating wholegrain high-fibre foods, and cutting down on alcohol and energy-dense foods
- find ways to fit more activity into your day, every day.
More information on healthy eating is available from: www.healthed.govt.nz