Monday, February 19, 2007

Weight Loss Study On Lean Pork Disregards Positive Role Of Dietary Fat

Dr. Wayne Campbell reveals a surprising weight loss power food--PORK!

It seems like we are seeing lots of research coming out all the time regarding the health and weight benefits of eating meat because of the healthy levels of protein it provides (some examples of these studies can be found here, here, and here). These exciting new scientific foundations for protein consumption are revealing what many of us who are livin' la vida low-carb have already discovered--protein and fat in animal-based foods are playing a major role in keeping hunger satisfied while aiding in permanent weight loss. It's about time, right?

This PR Newswire column today shares about another one of these kind of studies on the benefits of protein, this time zeroing in specifically on pork meat. However, there is one specific certain aspect of this research that is a bit disconcerting to me which I will address in a moment.

Lead researcher Dr. Wayne W. Campbell, associate professor of Foods And Nutrition in Purdue University's Laboratory for Integrative Research in Nutrition, Fitness and Aging, and his fellow researchers observed 46 overweight and obese women between the ages of 28 to 80 with a BMI of 26-37 over a period of 12 weeks. What they wanted to know was the impact of dietary protein on weight loss, appetite, mood, as well as cardiovascular and kidney health.

Each of the study participants were placed on one of two specific low-calorie diets:

NORMAL-PROTEIN (NP) GROUP--A 750-calorie diet with 18% protein
HIGH-PROTEIN (HP) GROUP--A 750-calorie diet with 30% protein

Both of these groups were also split into pre-obese and obese subcategories according to their BMI. The HP group was provided with 6 ounces of lean pork on average daily as part of their high-protein consumption.

At the end of the study, all of the participants involved had lost weight, fat mass, and lean body mass. But the lean body mass losses were less in the HP group than the NP group. In fact, the pre-obese HP group lost less lean body mass (3.3 pounds) than the obese NP group (6.2 pounds).

This lines up with previous research from Dr. Donald Layman and Anssi Manninen who both found that muscle mass is preserved on a high-protein, low-carb diet. Nothing is said about the carbohydrate or fat content of the diet Dr. Campbell put these study participants on, but we can infer from the lean pork that it was lower in fat and higher in carbs.

Additionally, the HP group experienced greater satiety than the NP group (something research has shown protein to provide), thus the perceived pleasure of the diet was increased with the HP group and decreased with the NP group. Finally, blood pressure and cholesterol levels improved for all groups while kidney function had no significant change, regardless of the protein consumption. These findings were important since people who oppose high-protein diets worry about damage to the kidneys and heart (although this recent study confirmed there are no heart health risks to a high-protein, low-carb diet).

The results of this study were published in this week's issue of the scientific journal Obesity.

Dr. Campbell said the presence of protein from the lean pork consumed by the HP group made the difference in weight loss and lean muscle mass preservation.

"After 12 weeks, our study found that the group of women who followed a reduced-calorie eating plan while consuming a higher level of protein was more effective in maintaining lean body mass during weight loss compared to those who consumed the same amount of calories with less protein," he said.

Maintaining muscle mass helps burn more calories which is crucial in bringing about faster weight loss and eventual weight control, Dr. Campbell added. Plus, hunger was a non-factor among the study participants who ate higher amounts of protein which led that group to feel more confident and energized as they went through their diet.

"The women on the higher protein diet rated themselves more positively in terms of overall mood and feelings of pleasure during dieting which could help dieters stay true to their weight loss plans longer," the researchers contended.

Interestingly, this was the first such study on high-protein diets on weight loss where pork was the primary source of the protein. While that is significant primarily as a marketing tool for the National Pork Board, who commissioned and funded this study, I believe they missed an excellent opportunity to educate and discuss the health benefits of consuming the fatty cuts of pork as part of a healthy diet, too.

There are studies underway right now that will turn the low-fat diet on its head when they show fat consumption, even saturated fat, is not fattening when combined with a low-carb diet. We already know fat is important for mental health and eating more fat and less carbs is good for heart health. Why must we obsess over finding the "lean" portions of pork? The researchers could have very easily placed the HP group on a high-fat, high-protein, low-carb diet and seen even better results.

But that's not what they did with their study which is a real shame. Trying to appease the low-fat crowd for whatever reason, the marketing people representing the pork industry highlighted the six cuts of pork that fall within the USDA's definition of the word "lean" for having less than 10g fat. Why hide and be ashamed of your best cuts of meat, hmmm? That's just selling yourself short and a great disservice to the public about the amazingly healthy products you have to offer them.

I'd love for Dr. Campbell and his researchers to do this exact same study again except this time make the HP group a high-fat and low-carb diet group as well--maybe a 40-50-10 diet ratio of protein-fat-carbohydrates. I would bet they would see a MUCH more pronounced difference in weight loss and lean muscle mass preservation among this HPHFLC group than any other diet comparison. How about it, Dr. Campbell? Are you and the pork people up to testing my theory?

Finally, this business of an extremely low-calorie diet scares the you know what out of me. They have been scientifically shown to cause bone loss and aren't necessarily a healthy way to eat. The sometimes lunatic advocates of calorie-restriction diets make me so glad I am livin' la vida low-carb and happily so. I could not imagine having to eat low-calorie forever, with or without protein.

You can e-mail Dr. Wayne Campbell about his research at

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Blogger Science4u1959 said...

History and anthropology shows that ancient tribes and civilizations always preferred the fatty meats. The Indians in the old West, for example, only hunted the fat animals, often even leaving the lean cuts of their catch for predators. If there was a shortage of fatty meats, for whatever reason, they would make it high in fat by adding fat. They would process the meat into pemmican, a 50/50 mixture of of lean, ground meat and fat and nothing else. For the Indian traveler, pemmican was considered a preferred food and these people performed incredible feats of endurance on this ultra-low-carb meat mixture.

Almost needless to say, obesity, diabetes, cancers, and almost all of our "modern" illnesses were completely unheard of. These people enjoyed extremely robust health.

Then again, they also had the significant advantage of the total absence of "experts" like diaticians, nutritionists and politically correct pathological liars. All of that was introduced with our "modern civilization"...

2/19/2007 9:01 PM  
Blogger Lady Atkins said...

750 calories a day!?! Good grief! Of course everyone lost weight!

Protein is important. I'm doing a lot more weight training now and really upping my protein. 16g for breakfast before my workout and 35g after (from two protein shakes mixed together).

After working out it's important to have whey protein to feed your muscle, and before bed I have casein protein (cottage cheese) to feed my muscle while I sleep.

2/19/2007 9:10 PM  
Blogger Science4u1959 said...

Of all the miserable diets from B to Z that I tried (read: suffered from) when I needed to lose weight, 12 years ago, one of those was hospital-supervised and consisted of 650 calories of watered-down orange juice, sucrose, and lemon juice. Not fresh but from some ready-made diet shake.

After 1 week the flabbergasted doctors had to admit defeat: I gained weight on it. Suffice to say I had enough too of doctors and their dietary delusions.

Since then I found the "A" in the aforementioned list of diets, and did my research and hence discovered the true scientific underpinnings of proper diet, my caloric intake is 3 times that number (often more) from fat, proteins, and some selected carbs - while I maintain weight. For me, the most important macronutrient is fat - immediately followed by high-quality, complete proteins. Fat intake, however, is some 60-65%.

2/19/2007 11:53 PM  
Blogger TESS said...

In order to lose 1 to 2 lbs a week I have to take in no more than 700 to 800 low carb calories. Not all people are lucky enough to be able to eat twice that and lose weight. The smaller you are the fewer calories you can eat(Staying Power by Drs Eades) You do a disservice to your readers by not ackknowledging that in some cases, primarily women I would suppose, calories do count. Even on a low carb diet. I also exercise 1 hour a day. If I didn't I would have to drop a little lower.

2/20/2007 7:56 AM  
Blogger Jimmy Moore said...

Hey Tess,

I hear where you are coming from and I certainly HAVE acknowledged that there are SOME people who should count calories along with their low-carb lifestyle to lose weight. But not for the majority of us.

If you are only eating 700-800 calories a week, then you are running dangerously close to harming yourself with malnutrition. The body was not made to take in less than around 1200 calories and be healthy.

Please talk with your doctor or nutritionist about your calorie intake. I don't know any medical professional who would advocate that few calories per day.

THANKS for your comments and concerns, Tess!

2/20/2007 11:10 AM  
Blogger Jeff Hamlin said...

I say she meant per day, but still only someone with a stomach the size of a softball would be able to subsist on that little an intake.

2/20/2007 5:04 PM  
Blogger Science4u1959 said...

Tess may suffer from a very slow metabolism as a result of thyroid problems, and/or perhaps some pancreatic condition as a result of (previous) insulin insensitivity. Adding coconut oil (2 tbsp in the morning, and evening with meals) to the diet often improves and boosts metabolism, as do regular meals. Several herbal treatments also can boost metabolism in a safe and natural way. Try to avoid iodized salt, use the best quality, natural sea salt instead. Most OTC and prescribed medications are also known to interfere with proper metabolism.
Perhaps it's a good idea for Tess to have that properly checked?

2/20/2007 8:28 PM  

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