Post by Jai D on Feb 1, 2010 15:20:30 GMT -5
Food myths and what the experts say
www.stuff.co.nz/life-style/wellbeing/3283175/Food-myths-and-what-the-experts-say
Helen Harvey talks to the experts and finds out we think a lot of silly things about food.
MYTH 1
Detox diets cleanse the body.
If you are thinking of going on a detox diet as a quick way to get rid of toxins, not to mention guilt, from overindulging during the festive season, think again.
The diets are quackery, AUT Professor of Nutrition Elaine Rush says.
"They are rubbish. There is no such thing ... It's a waste of money."
Detox diets show a total misunderstanding of how the body works, she says. Eating just one food or certain limited combinations of food can be dangerous. Food itself contains toxins – even good food – and too much of something is going to cause damage.
"We're a balancing act and we have to balance it with physical activity, healthy socialisation and not smoking.
"Smoking is the most toxifying thing I can think of."
The one diet that everyone should follow is an overall balanced diet with food from all food groups.
"You start messing with that and you are messing with your function as well."
Eat five or more servings of fruit and vegetables a day, good complex carbohydrates, lean meats, good sources of protein, low-fat dairy products and healthy oils, like olive oil and oily fish for the omega 3 fatty acids.
"I'd eat the oily fish rather than buy a supplement in a capsule. And sardines, herrings, tuna – all are excellent sources and relatively cheap, too."
Taranaki nutritionist Amanda Brien scoffs at "detoxing", too.
"You don't need to detox. The body is already good at detoxing, anyway.
"That's the job of your kidneys, liver, lungs – to filter out waste product."
People think they have overindulged and need the detox diet to make themselves "better", but they are probably doing themselves more damage.
"In reality, there is no one super food that is going to give you all the nutrients you need."
If someone is just having, say, water with lemon juice in it day in and day out, they are going to miss out on vitamins and minerals that come from the four food groups.
"You need to have variety every day," Miss Brien says.
Instead of the diet, get back into a healthy routine, she says.
MYTH 2
It's not what you eat, it's your metabolism.
According to the myth, if you sort out your metabolism, the weight will just fall off.
Not so.
Miss Brien says metabolism is the sum of different reactions that are going on in our bodies when they are breaking down food and transforming it into energy.
Ad Feedback
"It's influenced by heaps of different things by your age, by gender, by body weight and it's even influenced by climate.
"In summer, our metabolisms are higher than in the winter, because the temperatures are higher."
And people may be surprised to hear that people who are bigger, even overweight, have a higher metabolism than smaller people simply because they have a bigger body mass.
They have more muscle tissue and muscle requires more energy, so their metabolism is working faster.
"Everyone's metabolisms are slightly different, but they are not so hugely different that people can say: I've got a slow metabolism. It's harder for me to lose weight.
"At the end of the day, you are in control of what you eat and how much you are exercising and that impacts on your metabolism and then your weight."
It's an energy balance equation: energy in versus energy out. Keeping both sides of the coin equal maintains healthy weight.
"People justify having a chocolate bar because they walked to the dairy. It's not quite like that."
Professor Rush agrees.
"You are what you eat and you are your metabolism. "If your metabolism stopped, you'd be dead. Metabolism just means all the chemical reactions that take place in your body."
MYTH 3
You must drink eight glasses of water a day.
There has never been any scientific evidence to support the theory you should drink eight glasses of water a day, Professor Rush says.
For some people, it could be around the right amount but it all depends on body size, where you live, how much you sweat and how much activity you do.
"People who are healthy should be relying on their sense of thirst and realising there is water in other things ... cups of tea and coffee and also in fruit and vegetables. Lettuce is over 90 per cent water.
"You can get water from other sources."
People should go to the toilet regularly, once every two or three hours and check the colour is not too dark and not too light.
Miss Brien says the Ministry of Health recommends six to eight cups of water.
"Our bodies are about two-thirds water and need to keep hydrated. Water is in all the foods we eat as well."
MYTH 4
Body Mass Index is the best measure of fitness.
The Body Mass Index (BMI) is a crock, Professor Rush says. For adults, it is related to height, the calculation being weight divided by height squared.
"Forget about the BMI and talk about weight, because you are not going to change your height."
There is such a thing as being overweight, she says.
"And if your thighs are rubbing together, those sorts of things, you would be advantaged if you lost some weight."
People should be looking at other functional measures, like can they walk up six flights of stairs without puffing? Or can they walk quickly?
"The problem is there are a lot of skinny people around who are just as sick or on their way to chronic disease, particularly if you smoke. You could be more unhealthy than someone 10 or 15 BMI units higher."
A public health message in Britain advises people to make sure their waist measurement is less than half their height, she says.
"But it doesn't apply for everyone. If they can climb upstairs and they are eating a good diet, not smoking and they are happy, then it's much better than having a BMI less than 25 and hacking away."
Miss Brien says BMI is a contentious issue and has been debated quite a lot for a while.
"People take the numbers a bit too seriously."
Currently, the rule says normal weight is a BMI of 18.5 to 24.9 and anyone with a BMI of 25 or more is overweight and more at risk of disease. But it doesn't work for everyone.
It doesn't account for the type of body tissue people have, whether they have more fat or muscle tissue. "What type of body tissue you have determines your disease risk."
All Blacks, some of whom have a BMI of 30, which technically makes them obese, have a large body mass, but they are more muscular, so don't have the disease risk factors.
A better measure is waist measurement.
Women whose waists measure more than 80cm are at risk and the risk increases for those whose waists measure 88cm or more. For men, the measurements are 94cm and 104cm.
MYTH 5
You can't be fit if you are fat.
Professor Rush has one word for this statement: rubbish.
"If you look at swimmers who do these large distances, they have quite a lot of body fat, but it is essential to keep them warm.
"Different morphologies suit different people."
Pacific Islanders have more fat under the skin of their bodies compared with their arms and legs. Europeans have more fat on their arms and legs than they do on their body.
But other tests have to be taken before it can be said Europeans are healthier than Pacific peoples. Judging people just by their size and shape is silly.
"Fitness is more about how well your heart and lungs are functioning, whether you can walk up stairs without losing your breath," Miss Brien says.
People want to compare themselves to people in magazines.
"But it's more about how you're feeling and trying to maintain that healthy body weight over time."
So if you're noticing personally that, compared to last year, you have lost or put on a whole lot of weight, you might need to be concerned about that.
"Physically active people, even people who are overweight but physically active, have less risk of disease than people who aren't active at all and are thinner." Fairfax
www.stuff.co.nz/life-style/wellbeing/3283175/Food-myths-and-what-the-experts-say
Helen Harvey talks to the experts and finds out we think a lot of silly things about food.
MYTH 1
Detox diets cleanse the body.
If you are thinking of going on a detox diet as a quick way to get rid of toxins, not to mention guilt, from overindulging during the festive season, think again.
The diets are quackery, AUT Professor of Nutrition Elaine Rush says.
"They are rubbish. There is no such thing ... It's a waste of money."
Detox diets show a total misunderstanding of how the body works, she says. Eating just one food or certain limited combinations of food can be dangerous. Food itself contains toxins – even good food – and too much of something is going to cause damage.
"We're a balancing act and we have to balance it with physical activity, healthy socialisation and not smoking.
"Smoking is the most toxifying thing I can think of."
The one diet that everyone should follow is an overall balanced diet with food from all food groups.
"You start messing with that and you are messing with your function as well."
Eat five or more servings of fruit and vegetables a day, good complex carbohydrates, lean meats, good sources of protein, low-fat dairy products and healthy oils, like olive oil and oily fish for the omega 3 fatty acids.
"I'd eat the oily fish rather than buy a supplement in a capsule. And sardines, herrings, tuna – all are excellent sources and relatively cheap, too."
Taranaki nutritionist Amanda Brien scoffs at "detoxing", too.
"You don't need to detox. The body is already good at detoxing, anyway.
"That's the job of your kidneys, liver, lungs – to filter out waste product."
People think they have overindulged and need the detox diet to make themselves "better", but they are probably doing themselves more damage.
"In reality, there is no one super food that is going to give you all the nutrients you need."
If someone is just having, say, water with lemon juice in it day in and day out, they are going to miss out on vitamins and minerals that come from the four food groups.
"You need to have variety every day," Miss Brien says.
Instead of the diet, get back into a healthy routine, she says.
MYTH 2
It's not what you eat, it's your metabolism.
According to the myth, if you sort out your metabolism, the weight will just fall off.
Not so.
Miss Brien says metabolism is the sum of different reactions that are going on in our bodies when they are breaking down food and transforming it into energy.
Ad Feedback
"It's influenced by heaps of different things by your age, by gender, by body weight and it's even influenced by climate.
"In summer, our metabolisms are higher than in the winter, because the temperatures are higher."
And people may be surprised to hear that people who are bigger, even overweight, have a higher metabolism than smaller people simply because they have a bigger body mass.
They have more muscle tissue and muscle requires more energy, so their metabolism is working faster.
"Everyone's metabolisms are slightly different, but they are not so hugely different that people can say: I've got a slow metabolism. It's harder for me to lose weight.
"At the end of the day, you are in control of what you eat and how much you are exercising and that impacts on your metabolism and then your weight."
It's an energy balance equation: energy in versus energy out. Keeping both sides of the coin equal maintains healthy weight.
"People justify having a chocolate bar because they walked to the dairy. It's not quite like that."
Professor Rush agrees.
"You are what you eat and you are your metabolism. "If your metabolism stopped, you'd be dead. Metabolism just means all the chemical reactions that take place in your body."
MYTH 3
You must drink eight glasses of water a day.
There has never been any scientific evidence to support the theory you should drink eight glasses of water a day, Professor Rush says.
For some people, it could be around the right amount but it all depends on body size, where you live, how much you sweat and how much activity you do.
"People who are healthy should be relying on their sense of thirst and realising there is water in other things ... cups of tea and coffee and also in fruit and vegetables. Lettuce is over 90 per cent water.
"You can get water from other sources."
People should go to the toilet regularly, once every two or three hours and check the colour is not too dark and not too light.
Miss Brien says the Ministry of Health recommends six to eight cups of water.
"Our bodies are about two-thirds water and need to keep hydrated. Water is in all the foods we eat as well."
MYTH 4
Body Mass Index is the best measure of fitness.
The Body Mass Index (BMI) is a crock, Professor Rush says. For adults, it is related to height, the calculation being weight divided by height squared.
"Forget about the BMI and talk about weight, because you are not going to change your height."
There is such a thing as being overweight, she says.
"And if your thighs are rubbing together, those sorts of things, you would be advantaged if you lost some weight."
People should be looking at other functional measures, like can they walk up six flights of stairs without puffing? Or can they walk quickly?
"The problem is there are a lot of skinny people around who are just as sick or on their way to chronic disease, particularly if you smoke. You could be more unhealthy than someone 10 or 15 BMI units higher."
A public health message in Britain advises people to make sure their waist measurement is less than half their height, she says.
"But it doesn't apply for everyone. If they can climb upstairs and they are eating a good diet, not smoking and they are happy, then it's much better than having a BMI less than 25 and hacking away."
Miss Brien says BMI is a contentious issue and has been debated quite a lot for a while.
"People take the numbers a bit too seriously."
Currently, the rule says normal weight is a BMI of 18.5 to 24.9 and anyone with a BMI of 25 or more is overweight and more at risk of disease. But it doesn't work for everyone.
It doesn't account for the type of body tissue people have, whether they have more fat or muscle tissue. "What type of body tissue you have determines your disease risk."
All Blacks, some of whom have a BMI of 30, which technically makes them obese, have a large body mass, but they are more muscular, so don't have the disease risk factors.
A better measure is waist measurement.
Women whose waists measure more than 80cm are at risk and the risk increases for those whose waists measure 88cm or more. For men, the measurements are 94cm and 104cm.
MYTH 5
You can't be fit if you are fat.
Professor Rush has one word for this statement: rubbish.
"If you look at swimmers who do these large distances, they have quite a lot of body fat, but it is essential to keep them warm.
"Different morphologies suit different people."
Pacific Islanders have more fat under the skin of their bodies compared with their arms and legs. Europeans have more fat on their arms and legs than they do on their body.
But other tests have to be taken before it can be said Europeans are healthier than Pacific peoples. Judging people just by their size and shape is silly.
"Fitness is more about how well your heart and lungs are functioning, whether you can walk up stairs without losing your breath," Miss Brien says.
People want to compare themselves to people in magazines.
"But it's more about how you're feeling and trying to maintain that healthy body weight over time."
So if you're noticing personally that, compared to last year, you have lost or put on a whole lot of weight, you might need to be concerned about that.
"Physically active people, even people who are overweight but physically active, have less risk of disease than people who aren't active at all and are thinner." Fairfax