It supports previous evidence that a high-protein diet can reduce body weight and increase insulin sensitivity but suggests that the type of protein may also have a role to play.
If the findings are confirmed in people, they could have a significant impact on ingredients suppliers and manufacturers involved in the weight loss market and those catering to Atkins fans.
Researchers from the University of Adelaide and the Commonwealth Scientific and Industrial Research Organization also based in Adelaide, Australia, fed rats a high-fat diet (300g fat per kg) for nine weeks, then switched to a diet containing either 80 or 320g protein per kg, provided by either whey protein concentrate or red meat for six weeks.
High dietary protein reduced energy intake and visceral, subcutaneous and carcass fat, they report in this month's issue of the Journal of Nutrition (134:1454-1458).
Increasing the dietary density of whey protein, but not of red meat, reduced body weight gain by 4 per cent, they add, while whey protein also reduced plasma insulin concentration by 40 per cent and increased insulin sensitivity, compared to meat protein.
These findings support the conclusions that a high-protein diet reduces energy intake and adiposity and that whey protein is more effective than red meat in reducing body weight gain and increasing insulin sensitivity.
The development of new functional foods and drinks, particularly adult and sports nutrition products, has led to increased usage of whey protein concentrates and isolates, with 2002 consumption of all whey products at nearly 770,000 tonnes, acording to Zenith research.
The growing global production of cheese has generated ever-growing quantities of whey solids and to maximise the overall profitability of cheese and whey solids, the food industry is constantly on the look out to find new ways of process innovative high value-added whey derivatives - a trend equally applicable to both the protein and lactose part of whey solids.
According to the report, in 2002 consumption in West Europe edged up to nearly 770,000 tonnes for sweet whey, demineralised whey, whey protein concentrates (WPC) and whey protein isolates (WPI).
France, Germany and the Netherlands dominate whey production in western Europe, with the main whey processors located in these countries. The Dutch appear to have the greatest liking, accounting for more than 30 per cent of European consumption in 2002 - albeit that the Dutch animal feed sector is the main customer. Next on the list, food processing industries in France and Germany were responsible for 25 per cent and 15 per cent of the market respectively.
French companies like Euroserum are important in the sweet category, while Dutch company Borculo Domo is active in the demineralised category. According to the report, in WPC and WPI, Milei, Arla Foods and BBA Lactalis are each increasing their focus on added value products. Major dairy companies dominating the scene are Australian company Fonterra, Dutch DMV, French group Lactalis and Irish company Glanbia. A number of more specialised companies are also very active, these include Davisco, Armor Proteines and Tatua.