Q & A Month: why does yoghurt have a low GI?
Posted by kathryn in Carbohydrates and Q & A Thursday
Paul has asked the question – why do yoghurts that contain sugar still have a low GI?
Most yoghurts have a GI of between about 14 and 40. Despite the variety of scores, this puts yoghurt in the low GI category. Even the ones that contain sugar have a low GI.
In the pre-GI days of nutrition, carbohydrate foods were separated into two categories: simple and complex. This distinction was solely based on the stucture of the carbohydrate itself. It was believed complex carbohydrates were harder to breakdown and therefore better for you – because they kept you fuller for longer.
What affects the GI of a food?
However, research into the GI has shown it’s more complicated. Carbohydrate breakdown is less about the structure of the carbohydrate itself than the physical state of the carbohydrate in a particular food.
This can be seen when you compare the GI response of jasmine vs basmati rice.
The GI of a food can be affected by a number of factors including:
- the size of the carbohydrate particles
- the type of fibre in a food
- whether the food also contains fat
- how starch is stored in the food
What about yoghurt
Yoghurt contains carbohydrate, so it does impact blood sugar levels. However, it also contains other nutrients and has properties which slow down this glycemic response:
- yoghurt is slightly acidic
- yoghurt contains protein
- most yoghurt contains some fat
All these factors impact yoghurt’s GI, because they alter the rate at which your stomach empties food into the small intestines.
The GI is affected by the rate of digestion
After chewing and swallowing food, it travels down your oesophagus and hits your stomach. Your stomach is primarily concerned with breaking down proteins. Very little happens to carbohydrates in the stomach.
Instead it’s in the small intestines that carbohydrate absorption occurs. So any food which is held up in your stomach and only released slowly into the small intestines, will have a slower glycemic response.
The acidity of yoghurt, combined with it’s protein and fat, ensures a slow release into your small intestines. So yoghurt’s carbohydrate is broken down slowly and it has a low GI.
Yoghurt picture by Noranna under the terms of a creative commons license.
Life etc - how to cook oily fish
Posted by kathryn in All In A Day's Work
The latest issue of Life etc is out, complete with my Ten Minute Kitchen recipes using oily fish.
The three recipes are:
- Smoked salmon, dill and sour cream tartlets
- Barbecued sardines with fennel & mint salad
- Paprika crusted mackerel
The latest issue is available from newsagents. Or you can download the recipes from their website – if you click on the link in the right-hand column. It’s about half way down this page.
Quicklinks
Posted by kathryn in A Balanced Diet and Salads
- Tahini sauce: Tahini is a wonderful food and Cassie has this week posted a gorgeous recipe for tahini and caramelised onion sauce. I had this with roasted vegetables and tofu during the week . . . and it’s unbelievably good.
- Your bars: As you know I like a breakfast bar. And I wish, wish, wish these were available in Australia. At Your Bars you can construct your own snack bars. You choose the nuts, the dried fruit, whether you want tahini, spices, and an array of other ingredients. A few days later you’ll then receive a delivery of your very own personalised snack bars. Brilliant.
- Eating cake: I’m a big fan of a nice bit of cake – and so is British nutritionist Jane Clarke. In this article she explains how to making your own cakes makes a difference in the health stakes – because you’re in control of the ingredients. And thanks to Sophie for pointing me to this article.
- Pumpkin & white bean salad: I love the look of this pumpkin and white bean salad from Chocolate & Zucchini. It has a few ingredients, but anything with Moroccan spices, toasted pine nuts and fresh coriander has me hooked.
- Taking away the guilt: A bit of nutritional balance from this article on Reuters: Foods that aren’t as bad as you think.
- How to cheat: I grew up on Delia Smith and in my mum’s house she’s still the ultimate authority. But even my mum agrees Delia’s gone a bit astray if she’s recommending frozen mashed potato. Her latest book is all about How to Cheat – what convenience foods to use for the best results. Is this a good thing?
Photograph from Wikipedia.
Q & A Month: which is the healthiest bread?
Posted by kathryn in Shopping Basket, Carbohydrates and Q & A Thursday
The next question is all about bread. Wendy from A Wee Bit of Cooking fame asks:
What’s the best type to eat? Brown, wholemeal, seeded, rye . . .
Bread is a staple food for many. Different countries and different cultures have been baking bread for centuries. In our supermarkets bread often takes up a whole aisle of it’s own. It’s stocked by corner shops and service stations.
However, all bread’s are NOT created equal.
At the bottom end of the bread spectrum is most supermarket white bread. This kind of bread is a nutritional dud because:
- it’s low in fibre
- has a high GI
- unless it’s been fortified, white bread contains very few micronutrients.
Basically most supermarket white bread is a source of kilojoules, but not much else. Plus it’s high GI means those kilojoules won’t sustain you during the day.
But what’s the best bread?
There are about a hundred and one breads that aren’t white bread. There’s brown, wholemeal, wholegrain, sourdough, flat breads, pumpernickel . . .
But if I was picking my perfect bread it would:
- Be made from stone ground flour: Along with carbohydrates, grains contain protein, vitamin E, fibre and B vitamins. Conventional bread is made from flour that has been roller milled. This process removes everything but the starch / carbohydrate component of the grain – so you lose all the nutritional complexity. In contrast stone ground or stone milled flour is made by crushing the grain between rotating stones. The whole of the grain, with it’s full nutritional complexity is retained in the resultant flour.
- Be made from wholegrain flour: Whole meal bread is better than white. However here in Australia there’s often not a big difference between the two. Wholemeal is often just white flour with some of the fibre added back in. While the extra bit of fibre is good, you’re still missing out on the protein and vitamins. In contrast “wholegrain” means . . . well the whole of the grain has been used! Therefore you’re getting all the nutritional goodies from the grain.
- Include at least 2 different kinds of seeds: Seeds not only lower the GI of a bread, but they also add nutritional oomph. At the moment one of my favourite breads includes a smattering of pumpkin seeds. Which means I’m also getting a small dose of zinc, essential fatty acids, iron and calcium each time I have a slice.
- Be a sourdough: The sourdough culture makes bread slightly acidic. Research into the GI has found acidic foods take longer to leave your stomach and longer to digest. This means they have a lower GI and will give you more sustained energy.
My perfect bread would include all of these and it would be organic.
Buying better bread
If you can’t buy the best bread, you can still buy better bread.
Even if you just pick a couple of these criteria you’ll be eating a better bread. One with more fibre, a lower GI and plenty of nutritional goodness.
While you may not be able to buy organic sourdough, you can almost certainly find a wholegrain bread containing seeds. These are available from the supermarket. And if you can’t stand the seeds, then try for a wholegrain sourdough instead.
What is Q & A Month?
This post is part of Q & A Month. For those of you new to Limes & Lycopene, I usually run a fortnightly question and answer forum, called Q & A Thursday. But for the next four weeks, it’s Q & A Month. For more information you can take a look at the Q & A Thursday archives.
Q & A Month: is rice milk healthy?
Posted by kathryn in A Balanced Diet, Carbohydrates and Q & A Thursday
The eagle-eyed among you will have noted Q & A Month is turning into Q & A Six-Weeks! It’s proved very popular. I still have a question backlog to get through. But I’m hoping to finish with a flurry and answer the rest over the next seven days. Hoping anyway.
Moving quickly along then – the next question is from Claire and it’s about rice milk:
I would like to know if there is something wrong with drinking rice milk instead of soy or cow milk. I especially like it to cook porridge, as it is naturally sweet. But I always wonder if that sweetness doesn’t make it a milk to avoid . . . especially after reading everything you posted about high GI rices!
Nutrition value of rice milk
Like most rice, rice milk does have a high GI. While most soy milks hover around the 40 mark and cow’s milk is about 30, rice milk makes it all the way up to 79.
Here’s a run-down of the basic nutrient content of rice milk, compared to soy and cow’s:
- Kilojoules per 100ml: Rice milk 212kJ; Soy milk 271kJ; Skim milk 144kJ
- Protein: Rice milk 0.3% ; Soy milk 3.3%; Skim milk 3.6%
- Carbohydrate: Rice milk 10%; Soy milk 6%; Skim milk 5%
- Fat: Rice milk 1%; Soy milk 3%; Skim milk 0.2%
- Fibre: Rice milk <1%; Soy milk <1%; Skim milk 0%
- Calcium per 100ml: Rice milk 120mg; Soy milk varies but about 120mg; Skim milk 123mg
Is it healthy?
But . . . answering the “is it healthy” question is a lot more complex.
We as humans often like things to be black and white. And this is true of food. The answer to the question of is a food healthy is invariably it depends.
There are very few foods that are completely and utterly un-healthy. While there are also few foods that are 100 percent healthy. Instead everything lies somewhere between these two ends of the spectrum. All food has good and bad points. And whether it’s healthy or not depends on:
- what else you’re eating
- you’re level of activity
- if you have any health issues
- how much of that food you’re eating
A good example of this is rice milk. It’s high GI means it’s not the best food if you are trying to lose weight or have insulin resistance or diabetes.
Also if it was a major part of your daily diet and you were drinking several glassfuls a day, I’d caution you to cut down. It’s low protein and micronutrient content, means you’d be better off varying your diet and filling up on some other foods.
But if you’re soy and cow’s milk intolerant, rice milk is an obvious choice, no matter the GI.
Moreover, if none of these are you. And you enjoy rice milk in moderation, to sweeten up your morning porridge – then go right ahead.
What is Q & A Month?
This post is part of Q & A Month. For those of you new to Limes & Lycopene, I usually run a fortnightly question and answer forum, called Q & A Thursday. But for the next four weeks, it’s Q & A Month. For more information you can take a look at the Q & A Thursday archives.
Milk photograph by Steven’s Photography under the terms of a Creative Commons license.
Quicklinks
Posted by kathryn in A Balanced Diet, Weight loss, Breakfast, Salads and Soups
- Chickpea soup: Pinch My Salt has turned a hummous accident into a beautiful chickpea, ginger and coriander soup. It’s an excellent kitchen recovery and a delicious looking recipe.
- Spot the difference: Just Bento has posted pictures of two bento boxes. One of them has twice the kilojoules of the other – can you spot the difference?
- Beautiful coleslaw: I woke up this morning to find a winter coleslaw recipe on Mostly Eating. Crunchy vegetables, bound together with a yoghurt and mustard dressing – much better than the typical mayo. I like Sophie’s stance on raw vs cooked as well.
- Egg muffins: This weekend I’m planning to make Kalyn’s egg muffins. These little beauties have lots of protein, you can add some vegetables and they even freeze. They’re going to be perfect for my busy week ahead.
- On losing weight: Kira Cochrane has started a new blog on the Guardian website. Why does a woman who hates the diet industry and found putting on the weight quite liberating, want to lose it?
Q & A Month: How quickly does fruit and veg lose its goodness?
Posted by kathryn in Fruit, Vegetables and Q & A Thursday
Next on Q & A Month is a BIG and difficult question. Steve wants to know:
What is the deterioration rate of nutrients in fruit and vegetables – from the time they are picked, sold to you, kept in your fridge and finally eaten? Is it the same rate for all fruits and vegetables or do some lose their nutrients faster than others?
This is a really hard question to answer, as there are so many ifs, buts and variables. And at the moment my answer is going to be incomplete at best.
Why is it so hard?
The deterioration rate of nutrients depends on many, MANY things:
- how the food is grown
- how it’s harvested
- how it’s transported
- how it’s stored before and after purchase
- which nutrient we’re talking about
- which food we’re talking about
Plus, how much goodness you get from fruit and vegetables also depends on how you prepare them.
Different nutrients deteriorate at different rates
Vitamins, antioxidants and minerals all have different levels of stability. Vitamins C, most of the B vitamins and folate are really fragile. The minerals tend to be more robust. While some nutrients like the antioxidant lycopene, can actually increase in intensity and availability after picking. In some foods.
There’s some good information on this at the Choice website. They’ve tested the vitamin C and beta-carotene levels in six different vegetables. The results compares fresh vs cooked vs frozen. And they also show the difference between fresh and week old vegies. As you’ll see the deterioration rates vary quite significantly.
Choice also has this report on the freshness of the fruit and veg we buy. In it they note:
- English spinach retains only 53 percent of its folate and 54 percent of its carotenes after just eight days stored at fridge temperature.
- Frozen peas typically have 60 percent more carotene than ‘fresh’ peas and the vitamin C content is comparable with fresh peas that have been stored and then cooked.
There’s ongoing research into these issues. As far as I can tell it’s mostly being conducted by agricultural scientists. And much of it’s ultimately geared towards improving farming and food transport and handling practices.
But we’re a long way from a definitive answer to these questions.
What should you do?
- Eat your fruit and vegies. It’s still vital to eat two serves of fruit and at least five serves of vegies. In fact, given some deterioration does occur, it’s even more important to have plenty of fruit and veg.
- Try to shop seasonally. This ensures you’re getting fruit and veg at it’s peak. And minimises the amount of time it’s been stored.
- If you do a weekly shop, use the more perishable fruit and veg first. I try to use spinach and Asian greens within a couple of days of purchasing. While pumpkin, onions and carrots can be left until later in the week.
- Buy the freshest stuff you can. Go to farmers’ markets or shops that have a high turnover of fruit and veg.
- Don’t hesitate to use frozen vegies – they can have nutritional benefits.
What is Q & A Month?
This post is part of Q & A Month. For those of you new to Limes & Lycopene, I usually run a fortnightly question and answer forum, called Q & A Thursday. But for the next four weeks, it’s Q & A Month. If you have a question, or there’s a topic you’d like me to cover, leave a comment below or send me an email. For more information you can take a look at the Q & A Thursday archives.
Broccoli photograph by caro lines under the terms of a creative commons license.
And in the category of products that make me mad . . .
Posted by kathryn in Food & Health Myths
A friend just sent me this image, scanned from a magazine.
Apparently Diet Coke is now healthy.
Because it contains vitamins and antioxidants.
Two products. One provides “a little plus for your vitality and wellbeing”, while the other is for “today’s hectic lifestyle”.
Although there’s no information (I can find) on their website about what exactly is in these drinks.
Who do they think they’re kidding?
This leaves me speechless.
Heart Foundation Tick on . . . pizza?
Posted by kathryn in Health News
I’m briefly interrupting Q & A Month, because there’s some news I wanted to ask you about.
In the last few days the Heart Foundation have awarded their Tick to six pizzas from the Crust chain.
According to the Heart Foundation, they are “challenging pizza companies to provide healthier meals”:
The popularity of pizza can’t be ignored so it is great to see that a small local chain is the first pizza chain to prove that outlets can produce healthier pizzas which are still delicious.
This follows the 2007 awarding of a Tick to several McDonald’s meals.
What is the Tick?
Since 1989 the Heart Foundation has been awarding Ticks to food companies, when their products meet certain standards. The Tick means a particular brand is lower in salt, saturated fat, kilojoules and a number of other health indicators compared to other food in that category.
To meet the Tick criteria the Crust pizzas are
- made on a wholemeal base
- include a generous serving of vegetables
- use lean meat
- contain an average third of the salt and saturated fat of other leading chains
- have virtually no trans fat
- provide up to 80% of a day’s recommended fibre intake (for a male).
The Tick approved menu is here.
What do you think?
I have a close friend who works at the Heart Foundation. We discuss the Tick programme and so my views of this are coloured by those conversations and our friendship.
But I’m genuinely interested to know what you think.
Do you believe this is a positive and practical step by the Heart Foundation? Or are they muddying the waters and selling out?
Plus back to Q & A Month – and hopefully more regular blogging – tomorrow.
Photography by chocolate monster mel under the terms of a creative commons license.
Quicklinks
Posted by kathryn in Health News, Weight loss, Kid's nutrition and Soups
- Delicious soup: Poucan has a recipe for lemon and chickpea soup. It takes a bit of time to cook, but is super-easy and looks delicious.
- Watercress soup: I blame it on the rain we’ve had this week, but I can’t go past soup recipes. And Wendy has a doozy – watercress soup. Look at that vibrant green and just think of all the antioxidants.
- Food for fussy kids: Annabel Karmel’s website is all about food and nutrition for kids. There’s good information on weaning, plus recipes for children. I particularly like this cute fish pie.
- Attitudes to obesity: Paula Goodyer’s blog Chew on This is one of my favourites. This week she asks when does fat bashing go too far?.
- Beetroot news: New findings on the health benefits of beetroot this week. Although I’m not sure how many people are willing to drink 500ml of beetroot juice every day, given it’s beeturia effect.
- Curried egg salad: I made 101 Cookbooks curried egg salad for lunch this week and it’s delicious. I particularly like the way it’s mixed together with natural yoghurt instead of mayo.
Photograph by Virany under the terms of a creative commons license.
Should you worry about which foods contain the most antioxidants?
Posted by kathryn in Antioxidants and Q & A Thursday
Paul has asked:
I was just wondering, with all the great fresh fruits around, which have the highest amounts of antioxidants? I’ve heard pomegranates, but what about blueberries, and oranges?
I have to admit I find it hard to keep up with the list of top antioxidant containing foods. It seems to change with annoying regularity. At the moment I’m pretty sure it’s a toss up between acai berry and pomegranate juice. Although Indian gooseberries are also making a claim for the top spot. While a few years ago the number ones were wild blueberries and dried legumes.
While it’s interesting to know which foods are highest in antioxidants, I’m not sure how nutritionally useful this information is. For starters, the winners seem to have moved away from normal every day foods – the kind of things you’d buy at the supermarket. Goji, acai, pomegranate juice and billberries are not cheap. And I’ve no idea where you’d buy Indian gooseberries from.
Plus I find the idea of superfoods misleading. To concentrate on the foods that contain the most antioxidants implies they’re the only food you need. It gives the impression that if you eat this one, really expensive food, you’ll never have any health problems and you don’t have to bother with other fruit and veg.
But nothing could be further from the truth. The most important thing about antioxidants is to be having a variety. Neither pomegranate juice, billberries, nor even Indian gooseberries contain all the antioxidants you need.
Antioxidants are not one homogenous thing. There are actually many, MANY different kinds. They’re split into groups. For example:
- anthocyans found in berries
- flavonoids in apples, citrus, tea, potatoes
- carotenoids in carrots and green leafy vegies
- catechins in green tea, cinnamon and turmeric
- isothiocyanates in radishes and mustard
- indoles in broccoli and Brussels sprouts
- vitamin C in fruit and green vegetables
- the tocopherols in vegetable oils, nuts and avocado
However, even within these individual groups there’s a stack load of variety. If you concentrate on only a handful of foods you simply won’t get the mix and levels of antioxidants you need to be healthy, both now and into the future
What should you do?
My recommendation is to eat as many different kinds of fruit and vegetables as you can.
It’s easy to get into a rut when doing your grocery shopping. Buying the same fruit and veg each week. But break out of this habit. Instead buy different foods.
One of the simplest ways to make sure you’re getting a variety, is to buy different colours. Make sure your shopping basket contains:
- dark greens, such asspinach, brocolli, rocket and Asian greens
- lighter greens like kiwi fruit, green beans and zucchini
- oranges like pumpkin, honeydew melon and . . . oranges
- the reds of tomato, watermelon, red capsicum, chilli and beetroot
- dark blues and purples, such as berries and eggplant
- the white of onions and garlic
- yellows like squash and yellow capsicum
Ignore the superfoods. While oranges, blueberries and kiwi fruit may not be at the top of the antioxidant list, they’re still packed full of goodness.
What is Q & A Month?
This post is part of Q & A Month. For those of you new to Limes & Lycopene, I usually run a fortnightly question and answer forum, called Q & A Thursday. But for the next four weeks, it’s Q & A Month. If you have a question, or there’s a topic you’d like me to cover, leave a comment below or send me an email. For more information you can take a look at the Q & A Thursday archives.
Can you drink too much water?
Posted by kathryn in Q & A Thursday
I’m back from Melbourne. I’ve cleared my inbox and in-tray, so it’s time to continue with Q & A Month.
The next question is from Justine, who asks about water:
I over-indulged over Christmas and the New Year alcohol-wise, so am drinking lots & lots of water now I’m back at work. I’ve heard that too much water can be damaging . . . how much water is too much?
You’ve almost certainly heard how important it is to drink plenty of water and stay hydrated. However, while it’s rare, it is possible to drink too much.
What happens to the water you drink
In a normal situation, water makes up between 40 and 60 percent of your body weight. It’s highly regulated and controlled through a series of mechanisms, governed by hormones, your heart, kidneys and blood vessels. These restrict fluid losses if you’re dehydrated and bump them up when you’re taking in plenty of fluids.
We lose water every day through our lungs, skin and urine. This is replaced by the water we drink and also the water in the foods we eat.
Water intoxication
However, it’s also possible to drink too much water, which causes water intoxication. This happens when you take in more fluid than you can excrete in sweat or urine.
As your water content rises it dilutes the sodium levels in your blood. If your blood becomes less concentrated than the sodium in your cells, your body attempts to re-balance this by moving water from the blood into the cells.
As the cells become full of water, they start to swell. This is a big problem if it’s happening in your brain. There’s not a lot of space available in your skull. If cells start to swell and take up more space areas of your brain become compressed – which affects your brain’s functioning.
The symptoms are similar to those of being drunk – hence the name water intoxication. You become confused, lethargic, nauseous and can have headaches and slurred speech. If you don’t get medical attention, then this can lead to seizures, coma and death.
How much is too much?
But this is rare. The kidneys of a normal healthy adult can process up to fifteen litres of water a day. So you’re unlikely to suffer water intoxication, even if you drink a lot of water.
What is more crucial, is how quickly you drink the water. Water intoxication usually occurs when someone takes in several litres of water at one time, for example this woman involved in a water drinking competition.
How much water do you need?
Under normal conditions we need between 2.5 and 3 litres of water per day. You get this from the water your drink, plus the foods you eat.
For most people 8×250ml glasses (1 cup) will be sufficient. If it’s hot or you’re exercising, you will need more.
What is Q & A Month?
This post is part of Q & A Month. For those of you new to Limes & Lycopene, I usually run a fortnightly question and answer forum, called Q & A Thursday. But for the next four weeks, it’s Q & A Month. If you have a question, or there’s a topic you’d like me to cover, leave a comment below or send me an email. For more information you can take a look at the Q & A Thursday archives.
6 comments
29 February, 2008
