Monday, June 27, 2011

To Snack or Meal?

They say there was a time last century when we used to eat three meals a day and we should have been thankful for that many because kids were starving in Africa. I suspect they were talking about working adults between 1901 – 1970. I doubt whether kids, teenagers or housewives would have existed on three meals only. If they could sneak a biscuit, leftovers or some bread and dripping they would have gone for it.

Snacking & weight & diabetes

Today, for most readers, food is abundant and affordable and available 24 hours a day. That has led to the question from reader Ken Lynn regarding whether it is better for our weight and health to snack through the day or go back to the three meals a day like grandpa did.

A review by nutrition experts in Australia has looked at the research on snacking and health. There was no clear indication whether snacking had any long-term influence on body weight.

It has been theorised that snacking helps control the appetite and reduce hunger. Nice theory, no evidence. Others have suggested that snacking may cause over-eating, but most studies suggest we compensate to balance the kilojoules in the long-term whether we meal or snack. In other words, we tend to over-eat but snacking doesn’t seem to be the cause.

Snacking doesn’t appear to increase your chances of getting diabetes, nor did it seem to help control blood glucose if you had diabetes.

Snacking & the heart

On the other hand, people who snack and maintain their weight seem to have lower blood lipids (eg blood cholesterol and triglycerides). This link has been known for two decades or more, but we are reminded that these studies haven’t gone for longer than two months, so we don’t know the long-term effects. That’s the consistent problem with human studies of this nature is that they don’t go for long because they are so expensive to run.

Also remember that these types of studies don’t generate profits for a company. For example, if snacking was proven to reduce the chance of a heart attack, it won’t change the nutrition message – if you snack, snack smart on fruit, healthy sandwiches, low-fat, low-salt food bars etc. You see, no quick profit for anyone there because the message is the same.

So what is a snack?

Inherent in many eating research studies is that there is no definition of a snack. That cheese and salad sandwich may be a snack to you, a nibble to an elite athlete, but it might be a meal for grandma. You may recall that I discussed the confusion of snacks vs meals in an earlier blog.

What does it all mean?

I think it is still fair to say that, no matter when or how frequently you eat, your health and weight depends on what you choose to eat. Whether you __meal it__ or __snack it__ will be dictated by how you feel and what suits you. I breakfast, then snack, then finish the day with a meal. Perfect for me, but maybe not for you. In the US they say that snacking will become the norm.

Ken says he is 65 years and wants to crack 85 years. Well Ken, I reckon with a few smart food choices you can make 99 years. It is wise not to make it to 100 because dopey journos have nothing more original than to ask your secret to longevity.

If I ever make it that far my answer would be: “Secret to longevity? Air. Keep alternating an inhalation with an exhalation. Now get lost while I eat my cake.”

Reference: Nutrition & Dietetics 2011; 68: 60-64

GI & Rice

Hi Glenn,

I was wondering if you may be able to help me with a question that a few people have asked me and I am just not sure of the correct answer. I see many young women with polycystic ovarian syndrome who are often pre-diabetic or have diabetes. I encourage my clients and friends to eat a low GI diet and especially when it comes to rice I advise against eating rice such as Jasmine and white rice except for Basmati or Doongara rice.

Last week a friend said to me: "I was raised in an Asian family and our culture has survived just fine for centuries eating this rice and we still do and we are fine even though we eat it a few times every day". He went on to ask me why if they were not obese and didn't have diabetes why we recommend avoiding such rices.

I was wondering if you would mind sharing your thoughts with me on this question. With thanks in anticipation.

Warm regards,


Yes Ginette, having asked many folk of Asian background, they much prefer regular white rice rather than brown rice or a low GI rice and have eaten white rice for eons. A traditional white rice based diet also came with vegetables, a little meat, fruit, plenty of activity and a lean body. Under those circumstances they didn't need a low GI rice as the GI of the meal would have been lowered by the vegetables and meat they ate with the rice.

When you add loads of fat, cake, biscuits etc and little activity, very soon you gain weight and it becomes difficult to control blood glucose.

Similarly, there would be little harm in having full cream milk (regarding the fat content), if the rest of your diet was minimally processed, low fat foods. Now, it seems prudent to encourage people to have lower fat milk because they still want a biscuit with their cuppa. It's all about the total diet, more than a single food.

Today we have to give advice about single foods because humans are prone to just eating whatever they like, not what they need. And we find it so much easier to fret about a single food (Diet Coke, dollop of double cream or coffee) than to get a food in the context of a week of eating, or even a single meal.

Sunday, June 12, 2011

Coconut Water

As kids we would get whole coconuts from the shop, hammer a hole in two places with a tent peg, pour the water into a glass and drink some before we hammered the coconut to split it open so we could feast on the white flesh. All very exotic in the 1960s.

Now coconut water has gained public interest as a refreshment, especially with the allure of being a natural drink, not a concocted soft drink. Some have even suggested that coconut water has special properties and would make a good sports drink substitute.

Tropical fruit

Coconut water is the water from within the cavity of a coconut, and is not to be confused with coconut milk made from coconut flesh or the coconut oil used in food manufacture. People in tropical countries have enjoyed coconut water for centuries and it is the water of the young coconut that is prized the most, partly because it is sweeter, having a much higher fructose content. Coconuts are grown in about 90 tropical countries.

Potassium and sugars primary nutrients

You can see from the table below that coconut water has a very small amount of protein, virtually no fat, and a modest amount of carbohydrate in the form of sugars. It will quickly empty from the stomach and be absorbed readily by the small intestine. It is low in sodium and a good source of potassium, just like you would find in fruit juice. The sodium content is higher when the water is taken fresh direct from the coconut, around 30-100 mg in 100 mL.

I have compared the information with that of a popular brand in Australia. You can see that Cocobella is sweetened with sugar and pineapple juice because, like when I was a kid, the taste of coconut water wasn’t a winner. Then again, by the time a coconut reached outback South Australia in 1968, it wasn’t likely to be fresh. (Note: Divide kJ by 4.2 to get Cals).

Table. Coconut water per 100 mLs

Is it a health drink? A sports drink?**

Because it is low in sodium it isn’t similar to a sports drink, which has a modest amount of sodium to assist water absorption and retention in sport. Yet coconut water is very well suited as a regular drink with about half the sugar found in soft drinks. One small study indicated that coconut water was a good post-exercise rehydration drink, although it was rated as being less enjoyable than a sports drink. If you are doing plenty of exercise then the sports drink beats coconut water, but if you are looking for a lower kilojoule refreshment compared to soft drinks then a chilled coconut water could be the answer.

What does it all mean?

I suggest that you be really skeptical of any marketing health claims for coconut water. It does have a small amount of minerals and vitamins, but not really enough to get excited from a nutrition standpoint. Enjoy coconut water as a drink and a way to keep well hydrated during mild sweat loss, just note that it is not a substitute for a sports drink in endurance events. I can’t find a true “pure” coconut water in the supermarket around where I live; you may have more luck in the bigger cities or a health food store.


Medicine & Science in Sports & Exercise 2010; 42: 575

Molecules 2009; 14: 5144-5164

Soft drinks & acid

Bronwyn Webb wrote to me and said: "I didn’t realise that diet soft drink was bad for my teeth – I always assumed it was the sugar doing the damage and never thought about the acidity".

It's not just you Bronwyn, virtually everyone thinks that the sugar in the soft drink is what is responsible for any tooth problems. Carbohydrate food particles (eg bread, chips and even apple) that lodge between teeth and remain for some time can be eaten by bacteria in the mouth. While munching on the carbohydrate, the bacteria produce an acid that erodes enamel leading to tooth decay.

Drinks containing sugar don’t stay long enough in the mouth for the sugars to be consumed by bacteria. Excessive fruit juice, energy drinks, soft drinks and sports drinks can all cause enamel erosion through acids such as citric acid. Diet soft drink is as acidic as regular soft drink.

So, don't let those kind of drinks wash around inside the mouth. Drinking through a straw can minimise tooth contact with acidic drinks.