March 2009 Newsletter

Prof Mark Wahlqvist AO, MD, FRACP Immediate Past President International Union of Nutritional Science

Red meat and processed meat linked to higher mortality rates Low carbohydrate diets shown to reverse diabetes? Different weight loss diets compared: total calorie intake more important than amount of fat, protein, carbohydrate Partial meal replacements safe & effective for weight loss

Dr Antigone Kouris BSc (Biochem) (Melb), Hons (Nutrition) (Deakin), Grad Dip Diet (Deakin), PhD Med Nutrition (Monash) Honorary Nutrition Research Fellow, Monash Asia Institute

WHAT'S NEW IN RESEARCH

Red meat and processed meat linked to higher mortality rates

The new study by Sinha and colleagues (Archives of Internal Medicine March 2009; 169 (6): 562-571) about meat consumption and mortality in the US National Health Institutes –American Association of Retired Persons Study of some half million people, provides even more certainty that, in diverse populations, minimizing red meat intake and avoiding processed meats altogether is an important measure to reduce mortality from both cancer and cardiovascular disease. White meat in this study meant poultry and fish- for both men and women, it was protective against total mortality, cancer mortality and all other causes of death collectively assessed. This study was amongst White, Hispanic, Black, Asian and Native Americans .It is consistent with the Australian Health 2000 (Victorian Anti-Cancer Council ) of more than 30000 Australian ,Greek, and Italian born Victorians as well findings for meat and cancer more.

Low carbohydrate diets shown to reverse type 2 diabetes?
Westman and colleagues reported in the Journal of Nutrition and Metabolism in December 2008 that a low carbohydrate diet averaging about 50g/day and energy intake of 1500 calories/day resulted in 95% of the 48 participants with diabetes to either reduce or eliminate their diabetes medications after 6 months compared with only 62% of 49 participants in the higher carbohydrate (150g) but low GI diet also providing around 1400 calories/day. To put this in perspective, most people consume on average 250g/day carbohydrates (however alot of this may be from sugar dense foods!) so 50g/day is a severe reduction (e.g 1 slice of bread or fruit has 15g carbohydrate). This is an interesting study but one would have to double or triple their usual intake of vegetables (as they did in this sudy to 3 cups non strachy vegetables/day) to make up for the lack of cereal fibre and other nutrients - which could be seen as a positive outcome by some. Furthermore, the diet would become high in protein and fat: participants in this study were allowed to eat unlimited amounts of meat/fish/chicken/eggs, 120g yellow cheese/day, 60g cottage cheese/day resulting in protein intakes of around 110g/day (prior to diet intake was around 80g/day) and fat intake increased to 100g/day (from 88g/day) much of it coming from animal foods. In contrast, the higher carbohydrate diet provided about 50% less protein (67g/day) and fat (55g/day). The low carbohydrate diet resulted in significantly greater weight loss at 6 months (11kg) than the higher carbohydrate diet (7kg) and also greater improvements in blood sugars, blood fats (especially triglycerides) and blood pressure. more

Different weight loss diets compared: total calorie intake more important than amount of fat, protein and carbohydrates
Sack and colleagues reported in the New England of Journal of Medicine in February 2009 that reduced-calorie diets result in clinically meaningful weight loss regardless of which macronutrients they emphasize in 811 healthy overweight adults. They compared the following diets: low fat versus high fat; average protein versus high protein and high versus lowest carbohydrate diet. Each participant's caloric prescription represented a deficit of 750 kcal per day from baseline, as calculated from the person's resting energy expenditure and activity level. Satiety, hunger, satisfaction with the diet, and attendance at group sessions were similar for all diets. After 6 months, all groups had lost 6kg and had similar improvements in blood pressure, blood lipids and reduction in fasting insulin levels (except for the highest carbohydrate diet). The authors conclude"diets that are successful in causing weight loss can emphasize a range of fat, protein, and carbohydrate compositions that have beneficial effects on risk factors for cardiovascular disease and diabetes - such diets can also be tailored to individual patients on the basis of their personal and cultural preferences and may therefore have the best chance for long-term success". Please note, however, that these participants did not have diabetes and therefore problems with carbohydrate handling - the results may have been different if people with diabetes had been studied. more studies.

Partial meal replacements safe and effective for weight loss
Dr Gary Egger (well known for his Gut Buster program for men and Professor Trim's weight loss program for men) reviewed the evidence regarding partial meal replacements for weight loss in an editorial for the Medical Journal of Australia in 2006. Complete meal replacements are used in morbidly obese people who usually need to lose a lot of weight before surgery - all meals are replaced with a protein milk shake (also complete in vitamins and minerals) for around 6 weeks. In contrast, partial meal replacements can be used by people wanting to lose some weight but who are not necessarily obese. For initial weight loss, usually two meals a day are replaced with a protein milk shake while maintaining one other main meal in the first few weeks. This is usually followed by replacing one meal a day, usually lunch or dinner, to facilitate further weight loss or for weight maintenance. Results can also be achieved by replacing dinner with such protein shakes only a few times a week and many patients find this sustainable in the long term. His review concluded that clinical trials show that partial meal replacements are safe, acceptable and effective when used as part of an overall low energy diet and result in about 10% loss of body weight in 6-12 months or 6-8% loss in 1-5 years which is greater than weight loss achieved on diet alone.
HEC comment: If protein shakes replace dinner make sure that you have a decent lunch with lots of vegetables and a piece of fish/chicken more...
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NUTRITION RESOURCES ON THE WEB

Healthy Eating Game for kids "Planet Power" from the US http://mypyramid.gov/kids/kids_game.html
The game involves choosing food and drink for breakfast, lunch, dinner and snacks as well
as exercise/activity. The rocket ship needs to be fueled up with healthy food and activity tobe able to
blast off to planet power. If the player has picked too many calories, too few calories, too few foods
from one or more food groups or not enough activity then the rocket may have difficulty getting to
planet power. If that happens then the player has to try again but if the player gets to planet powder then
you get fireworks, music, a cartoon to watch and a certificate.
HEC Comment: this is a US website so some of the foods eaten are not familiar in Australia

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