Here’s the next part of a story I wrote recently for the New Zealand Healthy Food Guide. This looks at some of the issues teenage girls have to deal with.

“I’m fat.”

Compared to boys, teenage girls are more likely to struggle with their maturing body. Recently released results based on the 2007 Australian National Children’s Nutrition and Physical Activity Survey found that one-third of 9-13 year-old-girls were overweight. The figures are probably similar in New Zealand with the 2006-2007 New Zealand Health Survey finding that almost one-third of children up to the age of 14 were overweight or obese. One of the key differences between overweight and non-overweight teenage girls seems to be the amount of fruit and vegetables they eat each day. The more fruit and vegetables eaten, the less room for high kilojoule fizzy drinks and snack foods. As teenage girls become concerned about their appearance and body shape, negatively comparing themselves to the air-brushed images on TV, movies, billboards, and magazines, they may restrict the food they eat and increase their risk of nutrient deficiencies, especially calcium and iron.

Calcium – a critical window of opportunity

Teenage girls need just as much calcium as teenage boys – 1300mg which is about four glasses of milk a day – but it’s right at a time when many decide that they are ‘too fat’ and try to eat less food. A New Zealand study of 15-18 year-olds found that one-third of the boys and over one-third of the girls did not eat enough calcium. The latest results on Australian girls aged 14-16 found that 80% were not eating enough calcium! The teenage years are a critical ‘window of opportunity’ for building strong bones. Teenagers, more than any other age group, readily lay down calcium in their bones. It’s the key calcium storage period of our lives. The amount of calcium we store in our bones during these teenage years determines our peak bone mass. A high peak bone mass means we are less likely to suffer osteoporosis when we are older.

Teenage girls who diet and become too thin, who are not eating enough dairy foods or alternatives such as calcium fortified soy drink, canned fish and green leafy vegetables and who do very little exercise are at great risk of having weak bones.

“I’m vegetarian”

Teenage girls need twice as much iron as children or men but many are not eating that much. One study of New Zealand high school students found that 18% of the girls were iron deficient. Iron deficiency leads to tiredness and a weaker immune system with more likelihood of picking up colds and infections. Girls who decide to go vegetarian are especially at risk.

If your daughter is vegetarian encourage her to eat plenty of lentils, chickpeas, baked beans, dried beans, tofu, green leafy vegetables and iron fortified cereal. Make sure she has some vitamin C rich orange or kiwifruit with her meal to increase absorption.

If she is considering going vegetarian, get her to research how she will meet her daily iron needs. As a start, lay 100 grams of lean beef next to 2kg of silverbeet. They have the same amount of iron except that about 5% of the iron in silverbeet is absorbed compared to 25% from the beef. Check the reason she wants to go vegetarian. If it’s for weight control, get her to compare the kilojoules in 100 grams of lean beef to non-meat foods with similar absorbable iron content. Beef and Lamb New Zealand’s website has some good information about this.

Keep a variety of healthy snacks and foods in the pantry and fridge.

Write a list of healthy, low kilojoule school lunch ideas so she can pack her own lunch. Work on this together.

Encourage calcium rich, low kilojoule snacks such as low fat fruit smoothies, low fat yoghurt, canned salmon or sardines on wholemeal toast.

Encourage eating breakfast. “Sell’ it as one of the best weight control strategies. Make nutritious muesli with oats, nuts, seeds, wheat germ and dried fruit. Serve with low fat yoghurt and milk. Or make a fruit smoothie for breakfast on the run.

Encourage daily exercise to build strong bones.

Teach your daughter to be ad-savvy. If you have Photo-Shop on your computer, show her how they air-brush models. Chat about her favourite singer, athlete or movie star and discuss what they might eat and what effect it has on them.

Discuss what a healthy weight is.

Do not offer money as a reward for losing weight.

Do not offer food as a reward or comfort. Go for clothes instead.

Teach your daughter to recognise when she is full and how to stop eating when full.

Keep an eye out for these warning signs of an eating disorder:

• Excessive exercise
• Distorted body image – Saying she is too fat
• Per-occupation with food and calories
• Fear of weight gain
• Visiting the bathroom after eating
• Avoiding social situations with food