Dr. Robert Atkins has left his mark on several generations, including some to come. The founder of the Atkins Diet, and one of Time’s 2002 Persons of the Year, famously claimed that carbohydrates, not fats, are the weight-loss enemy. Even after his death 10 years ago, millions of Americans are still “counting carbs,” swearing they will reduce them someday.
Molly Michelman, a lecturer in the nutrition sciences program at the University of Nevada, Las Vegas, likes to emphasize carbohydrates’ importance in the diet. The macronutrient is necessary for things such as brain and nervous system function. But many of her students still take anti-carb stances.
“It’s like they’re coming clean,” she said. “They’ll talk about their diets and say, ‘Well, I had a lot of carbs today,’ like it’s something horrible.”
Many medical and exercise experts have emphasized protein. There is plenty of research to back the idea that higher protein levels will help blood glucose regulation and can bring other health benefits. Protein is a necessary macronutrient, too, which helps muscle cell regeneration, immune system support and tissue synthesis, said Jessica Crandall, a registered dietitian with Denver Wellness and Nutrition in Colorado.
But both Michelman and Crandall stress moderation for both protein and carbohydrate intake. There are plenty of good and bad choices to make on both fronts, they say.
High protein levels
It’s not uncommon for fitness trainers to recommend high levels of protein intake for weight-loss clients. Bodybuilders and athletes also seem to follow similar guidelines. But Crandall said there is plenty of research that suggests excessive protein does not boost athletic performance, nor does it really build muscle. Instead, organs such as the kidneys and liver simply work overtime to expel the extra protein.
“Adding more soap to the dishwasher isn’t going to make the dishes cleaner,” she said. “You’re not going to bulk up more.”
So how much protein should the average person take in?
The Acceptable Macronutrient Distribution Range, or AMDR, created by the National Academy of Sciences, says protein ranges should run about 10 to 35 percent of caloric intake. But Michelman thinks this suggestion offers too broad of a range and recommends a long-held dietitian recommendation of between 0.8 to 1 gram of protein per kilogram of body weight.
To calculate your body weight in kilograms, divide your weight in pounds by 2.2.
For example, a 200-pound man would weigh about 91 kilograms, bringing a protein recommendation of 72.8 to 91 grams a day. For a 130-pound woman, at 59 kilograms, the range is between 47.2 to 59 grams.
Crandall acknowledged that some sports scientists recommend as much as 2 grams of protein per kilogram. While she considers each client’s activity level, age and other characteristics, she said that going above 1.8 grams per kilogram is simply unhealthy.
“When you go beyond that (1.8 grams per kilogram), something to think about is that protein is made up of nitrogen,” she said, “and that means extra work for the kidneys to break that down, and that’s additional stress.”
Our daily protein needs are also probably more easily met than one would assume.
“People in the U.S. don’t struggle with getting enough protein, assuming they are not in an impoverished situation,” Michelman said. “A 3-ounce piece of meat, which is about the size of a deck of cards, has more than 20 grams of protein in it. You’d have to try really hard not to eat enough.”
Although she may not agree with them, Michelman understands more aggressive protein recommendations for weight loss. For one thing, she said, the body works harder to digest protein, resulting in more calories burned. Protein also helps people feel fuller for longer, reducing hunger.
But Ronald Hedger, assistant dean of clinical skills at Touro University Nevada College of Osteopathic Medicine, said excessive protein for long periods could lead to compromised kidney and liver function and even heart constriction.
“My take on diets in general is that they go overboard,” he said. “And I’m not a big fan of high protein diets for long-term use.”
Hedger recommends a high-protein, carb-restricted diet be undertaken for no more than three or four months. Sustaining weight loss after a high- protein, low-carbohydrate diet is also difficult. Crandall said she sees plenty of clients who lost a lot of weight this way, but gained back even more.
“The carbohydrate is still the body’s preferred source of fuel,” Michelman added. “We want to teach the person to eat in a healthy way with variety and eat in some way that’s not going to be hard to continue for an extended period of time once you get to your goal.”
Often when people increase protein and limit carbohydrates, they omit fiber sources such as fruits and vegetables. With a nation already low on fiber, Michelman said, problems such as constipation are common with high-protein diets.
“Most people don’t have enough fiber in their diets, period,” she said. “People eat a bowl of oatmeal with a measly 2 or 3 grams of fiber in it and think they’re doing fine. ... You need 25 to 38 grams a day.”
Medical experts also recommend a variety of protein sources. Free-range, grass-fed and hormone-free meats are always preferred. But these meat sources come at a higher monetary cost some are not willing or able to pay. When it comes to seafood, protein sources such as salmon can come with their share of misleading information, Hedger said. Farm-raised salmon can be fatty, outweighing some of its protein benefits, he said, while salmon caught from the wild tends to have a much lower fat content.
Quality issues aside, there is also a need to understand “complete proteins,” or ones that contain all the nine essential amino acids the body requires from food sources. Complete proteins such as meat, eggs, seafood, dairy and soy offer the full health benefits protein is intended to give the body, while incomplete sources such as beans and nuts don’t.
Beans and nuts require important food combining techniques to make sure all the amino acids are available to the body. Beans, for example, carry the complete amino acid set when combined with rice. And peanut butter is incomplete without bread. Lentils, a high-protein food, also need a grain with them. Quinoa, however, is considered a complete protein.
“When we get really concerned about this is with vegans (who don’t eat eggs, dairy or meat). That’s when food combining is really important,” Michelman said.
For meat-eaters or vegetarians who may still eat dairy or eggs, Hedger recommends Greek yogurt and eggs in moderation as good protein sources. The American Heart Association says people can eat up to one egg a day without negatively affecting cholesterol levels. Watching serving sizes is also key, Hedger added.
“I tell people to think of it as intuitive eating. If you take a truly measured portion of cereal, beef or chicken, eat like that throughout the course of the day, but stop when you’re full, you’ll be fine,” Hedger said. “But Americans eat so much more because we’re offered more. We pay for it and we’re going to eat it even if it kills us.”
The experts caution against overusing protein shakes or meal replacement bars as protein sources. On occasion, when someone is on the go, these foods are acceptable, Crandall said. But she would prefer to explore quick ways for clients to cook fresh protein sources instead. She also advises clients on how to read meal replacement labels.
“Make sure you know what’s in it. Make sure the protein source is whey, soy or egg-based,” Crandall said. “Collagen-based ones are incomplete proteins.”
Crandall also cautions against high-fat meal replacement shakes and to watch for added sugars, such as maltodextrin, dextrin and sucrose. A tip she gives clients is to watch for the endings -ose and -ol on ingredients, particularly the latter, which is a sugar alcohol that can cause an upset stomach in some people.
Michelman is skeptical about the numerous additives in high-protein meal replacement foods or shakes.
“People should get what they need from real food. It (a meal replacement) doesn’t teach you how to eat,” she said. “Can anyone comfortably look at that laundry list of ingredients and really know what these things are?”