Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Is one diet as good as another? U of I study says no and tells you why

06.03.2009
Any diet will do? Not if you want to lose fat instead of muscle. Not if you want to lower your triglyceride levels so you'll be less likely to develop diabetes and heart disease. Not if you want to avoid cravings that tempt you to cheat on your diet. And not if you want to keep the weight off long-term.

"Our latest study shows you have a better chance of achieving all these goals if you follow a diet that is moderately high in protein," said Donald Layman, a University of Illinois professor emeritus of nutrition. The research was published in the March Journal of Nutrition.

Layman's new study followed the weight-loss efforts of 130 persons at two sites, the U of I and Penn State University, during 4 months of active weight loss and 8 months of maintenance.

Two previous studies had looked at short-term weight loss; this one was designed to look at long-term effects, he said.

Although both plans were equal in calories, half the group followed a moderate-protein diet (40% carbohydrates, 30% protein, 30% fat) while the other followed a diet based on USDA's food-guide pyramid (55% carbohydrates, 15% protein, 15% fat).

"Persons in the first group ate twice the amount of protein as the second group," said Layman.

And the difference in protein made all the difference in improved body composition and body lipids, he said.

Although the amount of weight lost in both groups was similar, at 4 months participants in the protein group had lost 22 percent more body fat than members of the food-pyramid group. At 12 months, the moderate-protein dieters had lost 38 percent more body fat.

"The additional protein helped dieters preserve muscle. That's important for long-term weight loss because muscle burns calories—if you lose muscle, and you used to be able to consume 2,000 calories without gaining weight, you'll find that now you can only eat, say, 1,800 calories without weight gain," he said.

What were the effects on lipids? Although at 4 months the food-guide pyramid appeared to be more effective in lowering LDL and total cholesterol levels, at 12 months LDL levels came back up until both diets were equally effective, Layman said.

"This is the first study to show that short-term changes in LDL cholesterol are not maintained with long-term weight loss. Most scientists believe that high cholesterol is more a factor of genetics than of diet," he said.

But the moderate-protein diet had by far the bigger effect on lowering triglycerides, and that lasted as long as individuals remained on the diet, he said.

"Of the two types of lipid problems, high triglycerides pose a greater risk for heart disease. Approximately twice as many people have high triglycerides, and people with this condition are approximately four times more likely to die from heart disease," the scientist said.

To ensure compliance, participants met every week for weigh-ins and nutrition instruction. "We taught participants how to follow their diet, how to grocery shop, and how to prepare the meals. They also measured everything they ate three days a week," he said.

"Studies that report there is no difference among diets also report that subjects were not carefully following the diets," said Layman. "It's very important to realize the difference between diet compliance and diet effectiveness."

The protein diet was easier to follow and maintain long-term, with 64 percent of the moderate-protein dieters completing the study compared to 45 percent of dieters using the high-carbohydrate diet, Layman said.

"Subjects on the moderate-protein diet reported that they weren't as interested in snacks or desserts, and they didn't have food cravings. When you eat protein, you feel full longer," he said.

Average weight loss for the protein group was 23 percent higher than the food-pyramid group, with 31 percent of "completers" in the protein group losing more of than 10 percent of their initial body weight versus 21 percent of the food-pyramid group.

Phyllis Picklesimer | EurekAlert!
Further information:
http://www.uiuc.edu

More articles from Studies and Analyses:

nachricht New study from the University of Halle: How climate change alters plant growth
12.01.2018 | Martin-Luther-Universität Halle-Wittenberg

nachricht Disarray in the brain
18.12.2017 | Universität zu Lübeck

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>