Useful, interesting information about the Zone Diet plan.

Monday, February 14, 2005

Understanding Eicosanoids

Understanding eicosanoids and their function in the body is vital to understanding why the Zone Diet works. Here's a great article on the subject from Dr. Sears...
Strange, mysterious, and almost mystical, eicosanoids are the key to our health because they control the flow of information in our Biological Internet. Why are eicosanoids so important? They were the first hormones developed by living organisms more than 550 million years ago. As such they can be considered "super-hormones" because they control the hormonal actions of other hormones. Furthermore, you don't have an eicosanoid gland since every one of your 60 trillion cells can make eicosanoids.

Even though they are earliest hormones (dating from 550 million years ago), eicosanoids only were identified in the 20th century starting with the discovery of essential fatty acids in 1929. It was found that if fat in the diet was totally removed, rats would soon die. Adding back certain essential fats (then called Vitamin F) was found to enable fat-deprived rats to live. Eventually as technologies advanced, researchers realized that essential fats were composed of both Omega-6 and Omega-3 fatty acids that both needed to be obtained in the diet because the body could not synthesize them. The word eicosanoids is derived from the Greek word for 20 which is eicosa, since all of these hormones are synthesized from essential fatty acids that are 20 carbon atoms in length.

Sunday, November 28, 2004

Zone diet wins in varsity study

Otago University has found that overweight women lose weight more quickly on the Zone diet than if they follow conventional dietary advice

A study by the university's Edgar National Centre for Diabetes Research found that women also lost weight faster on the controversial Atkins diet, but they started to gain weight again within a year.

The study concludes that the Zone diet, promoted by American doctor Barry Sears, "may be the best overall approach to reducing the risk of cardiovascular disease and Type 2 diabetes".

The lead researcher, Dr Kirsten McAuley, said that although thousands of studies had been made of the Atkins diet, the Otago research was the world's first direct comparison of Atkins, Zone and conventional dietary advice in a test which did not have a high dropout rate.

Eighty-eight per cent of the overweight Dunedin women in the study stuck it out for at least a year, providing data on 96 women with an average age of 45.

All were "insulin-resistant", a pre-diabetic condition where the body's ability to use insulin to absorb sugar is reduced.

In full diabetics, insulin resistance causes a dangerous buildup of blood sugar which the body cannot absorb.

In the pre-diabetic stage, the body copes by producing more insulin.

The women were divided into three groups - one on the Atkins diet, one on the Zone diet and the third being given conventional diet advice.

The Atkins and Zone diets aim to slash intake of carbohydrates, including sugar.

Dr McAuley said the Atkins was more extreme, starting with 20g of carbohydrates a day, equivalent to half a slice of toast or half a banana.

The Zone diet emphasises high protein foods to offset low carbohydrates, advocating a balance of one-third low-fat protein such as meat, eggs and beans, and two-thirds fruit and vegetables.

Conventional dietary advice also emphasises eating plenty of fruit and vegetables, but with less emphasis on meat because of worries about high fat increasing the heart attack risk.

Researcher Kylie Smith told the first conference of the New Zealand branch of the Australasian Society for the Study of Obesity in Auckland yesterday that all the women in the study were seen weekly for four months and then checked again at six months and a year.

After six months the women on the Atkins and Zone diets had lost an average of 8kg. Women following conventional advice lost only 5kg.

After a year, the Atkins dieters were gaining weight again and were 5.4kg below their starting points. The conventional eaters were still 4.5kg lighter, and the Zoners were the winners with average weights 6.5kg below where they started.

Dr McAuley warned that diabetics with signs of kidney disease should avoid the Zone diet.

"There is no one best bet or wonder diet that's going to solve obesity," she said. "We need to consider a variety of options for different people who have different eating habits and preferences."

Surprisingly, the study found that after six months, women on all three diets had about the same amount of "bad" LDL cholesterol, the main warning signal for heart attacks.

"It was expected that LDL would increase under the Atkins diet," Ms Smith said.

Atkins allows people to eat high-fat steaks as long as they have minimal carbohydrates.

After two months, the conventional eaters were getting 49 per cent of their energy calories from carbohydrates, compared with 34 per cent for the Zoners and 11 per cent under the Atkins diet.

But the Atkins dieters paid a painful price - "a significant number" needed to take anti-constipation pills because they missed out on bread and other high-fibre foods.

They ate an average of only 9g a day of dietary fibre, compared with about 20g a day for both the other two groups.

"Those on the Zone diet did seem to enjoy it better," Ms Smith said.

How old and new compare


* Eat plenty of fruit and veges (at least two fruits and three vegetables a day).

* Eat plenty of breads and cereals, preferably wholegrain (six daily slices of bread, half-cups of breakfast cereal or cups of rice or pasta).

* Drink low-fat milk and dairy products (two daily glasses of milk or pottles of yoghurt or four slices of cheese).

* Eat one serving a day of meat, eggs and nuts (two slices of meat, one steak, one chicken leg, one fish fillet, one egg or three-quarters of a cup of beans).

* Aim to get calories from carbohydrates 50-55 per cent, fat 30-33 per cent (including 8-10 per cent saturated fat), protein 11-15 per cent.

* Aim for 30g of fibre a day from vegetables, wholegrains, beans and peas.


* Initial daily limit of 20g of carbohydrate, obtained from unprocessed salads and other non-starchy vegetables. Avoid high-sugar processed foods such as bread, rice, pasta or vegetables grown underground.

* Eat mainly meat, dairy products and salad vegetables to keep you full.

* Gradually increase carbohydrates such as high-fibre veges, fruits, beans, peas and wholegrains to the level that keeps your body at the right weight.

* Take multivitamin pills and an essential oils/fatty acid formula to ensure adequate nutrition.

* No precise aims for calorie intake proportions, but very low carbohydrate means high proteins and fats.


* Eat at last three meals and two snacks a day to stay within the "zone" where you are not hungry and have a clear mental focus.

* Divide your plate into three equal sections. One-third should be enough low-fat protein to fit in the palm of your hand, and two-thirds should be fruits and vegetables, with a dash of fat such as olive oil.

* Eat plenty of leafy green vegetables and fruits.

* Eat less pasta, breads, grains and starches.

* Aim to get calories from protein 30 per cent, fat 30 per cent, carbohydrates 40 per cent.

Related resources:

Australasian Society for the Study of Obesity

Sunday, October 31, 2004

Zone Tips for Vegetarians

From Zone Diet Advantage:
Is it possible to be vegetarian and remain satisfied and nourished in the Zone? "Very easily!" responds Dr. Sears. "You just have to make sure that you have adequate levels of vegetable protein at each meal. This can be either tofu or soybean imitation-meat products," he advises.

The problem with traditional vegetarian diets: "They're hormonally unbalanced because they contain huge amounts of carbohydrates and little else. Eating a diet based almost solely on carbohydrates causes insulin levels to soar, which causes blood sugar levels to drop quickly," Dr. Sears cautions. As a result, many vegetarians find themselves feeling sluggish, always searching for more food, and, sometimes, gaining weight.

You can find a wide range of balanced but meat-free recipes via the Zone Diet's online Meal Plan and Recipe Search. "When planning your meals and snacks, remember that you should use the same methods—hand-eye, blocks—that meat eaters use to create their meals," says Dr. Sears. And, finally, "make sure you get the right supplements, including the B-complex vitamins—I recommend 50 micrograms of vitamin B-12 a day for vegetarians—and iron (as well as other minerals), plus DHA from algae."

Here, a sample day's menu in the vegetarian Zone:

Breakfast: Asparagus Frittata
Lunch: Greek Salad with Garlic-Oregano Dressing
Snack: Berry Smoothie (with protein powder)
Dinner: Tempeh Paprikas
Learn more at the Zone Diet Advantage web site...