By Jack Challem
The word protein comes from an ancient Greek word meaning of greatest importance. And that points to how fundamental protein is to health. It’s the chemical workhorse of the body, and the building block of skin, internal organs, hormones, and enzymes.
Despite its great importance, protein has endured much controversy over the past 40 years. The reason goes back to Dr. Robert Atkins’ high-protein, low-carbohydrate diet—once thought to be dangerous.
How could protein be dangerous? For many years, doctors and dietitians believed that high-protein diets translated to high-saturated-fat diets, which could increase the risk of heart disease. But guess what? For one thing, protein isn’t always loaded with saturated fat. Second, there’s controversy about whether saturated fat deserves its bad rap. And since Dr. Atkins died in 2003, the tide of medical research has turned in his favor. Another reason high-protein diets have been questioned is because some people think that too much protein is bad for your kidneys (see note of caution, below), but this appears to be true only for people with impaired kidney function. Bottom line: for most people, eating more protein may help with weight loss and improved glycemic control.
Eating a high-protein diet may help with weight loss for several reasons. According to the Harvard School of Public Health, people tend to feel full fuller on fewer calories after eating protein than they do after eating carbohydrates or fat. Protein can also help curb cravings, and help you eat less. In a study published in June 2013 in the European Journal of Nutrition, people who included a source of protein—in this case, an egg—with breakfast reported feeling more full and less hungry than those who ate a lower-protein, higher-carb breakfast. They also ate less at lunch and dinner.
A diet that’s rich in protein may also help people with diabetes to better manage their blood sugar. A study published in March 2014 in the Journal of Nutrition compared the effects of a high-protein breakfast to a high-carb breakfast in people with type 2 diabetes. The high-protein breakfast lowered blood sugar levels after both lunch and breakfast. The participants who ate the high-protein breakfast also had slightly elevated insulin levels after lunch, which indicates their bodies were working to properly control blood sugar. Another study, published in 2015 in Diabetologoia, compared the effects of two high-protein diets—one high in animal protein, and one high in plant protein—in 37 people with type 2 diabetes. Liver fat and A1C levels were reduced, and liver enzyme tests improved in all people. Additionally, insulin sensitivity improved in people on the high-animal-protein diet, and kidney function improved in people on the high-plant-protein diet.
A study published in September 2014 in the Annals of Internal Medicine compared the effects of low-carb diets and low-fat diets in 148 men and women. The study found that the low-carb diet resulted in greater weight loss and reductions in cardiovascular risk factors than the low-fat diet. People on the low-carb diet, which was high in protein and fat, showed greater improvements in body composition, HDL cholesterol level, ratio of total to HDL cholesterol, triglyceride level, and 10-year coronary heart disease risk.
How to Eat
You don’t have to go on a strict Atkins-style diet to see your health improve. Even moderate increases in protein and decreases in carbohydrates may help.
When it comes to eating a protein-rich diet, it’s not just the amount of protein, but the quality of the protein sources that matters. To put a protein-rich diet into practice, eat a variety of proteins. The Harvard School of Public Health recommends limiting red meat and processed meat, and focusing on healthy sources of protein such as fish, lean meat, poultry, and legumes (beans, peanuts, lentils, snow peas, sugar snaps). Just remember that legumes also contain carbohydrate, so eat small portions at a time, and test to see how your blood sugar reacts. Along with that protein, get plenty of non-starchy, high-fiber vegetables and fruits, including salad greens, tomatoes, broccoli, cauliflower, raspberries, blueberries, and kiwifruit. Not only are these plant foods brimming with health-giving nutrients, the fiber in them helps to stabilize blood sugar levels.
Note of caution: Patients with end-stage kidney failure are routinely advised to limit their protein intake. That’s because eating too much protein can put extra strain on the kidneys, worsening kidney function in people with kidney problems. If you have been diagnosed with any type of kidney problem—even a mild reduction in kidney function—please consult with your physician before adopting a higher-protein diet.
Jack Challem, The Nutrition Reporter™, is a member of the American Society for Nutrition and one of America’s most trusted nutrition and health writers. He is the bestselling author of more than 20 books, including Stop Prediabetes Now, and he gives nutrition presentations across the United States and around the world, including Tokyo, London, and Istanbul. Free, downloadable excerpts from his books and sample issues of his newsletter are available at www.nutritionreporter.com.
Bazzano, L.A., Hu, T., Reynolds, K., et al. “Effects of Low-Carbohydrate and Low-Fat Diets: A Randomized Trial.” Annals of Internal Medicine. September 2, 2014. http://annals.org/aim/article/1900694/effects-low-carbohydrate-low-fat-diets-randomized-trial.
Fallaize, R., Wilson, L., Gray, J., et al. “Variation in the Effects of Three Different Breakfast Meals on Subjective Satiety and Subsequent Intake of Energy at Lunch and Evening Meal.” U.S. National Library of Medicine and National Institutes of Health. September 5, 2012. https://www.ncbi.nlm.nih.gov/pubmed/22948783.
Harvard School of Public Health. “Obesity Prevention Source: Food and Diet.” Accessed November 21, 2016. https://www.hsph.harvard.edu/obesity-prevention-source/obesity-causes/diet-and-weight/.
Harvard School of Public Health. “Protein.” Accessed November 21, 2016. https://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/protein/.
Markova, M., Hornemann, S., Sucher, S., et al. “Metabolic and Molecular Effects of a High-Protein Diet in Subjects with Type 2 Diabetes.” Journal of Clinical Diabetology. September 2015. http://jcdonline.in/wp-content/uploads/2016/02/6.JCD_Volume_2__Issue_3_Journal_Watch.pdf.
Papakonstantinou, E., Triantafillidou, D., Panagiotakes, D.B., et al. “A High-Protein Low-Fat Diet is More Effective in Improving Blood Pressure and Triglycerides in Calorie-Restricted Obese Individuals with Newly-Diagnosed Type 2 Diabetes.” European Journal of Clinical Nutrition. March 2010. http://www.nature.com/ejcn/journal/v64/n6/full/ejcn201029a.html.
Park, Y.M., Heden, T.D., Liu, Y., et al. “A High-Protein Breakfast Induces Greater Insulin and Glucose-Dependent Insulinotropic Peptide Responses to a Subsequent Lunch Meal in Individuals with Type 2 Diabetes.” The Journal of Nutrition. November 26, 2014. http://jn.nutrition.org/content/early/2014/12/24/jn.114.202549.
Te Morenga, L.A., Levers, M.T., Williams, S.M., et al. “Comparison of High-Protein and High-Fiber Weight-Loss Diets in Women with Risk Factors for the Metabolic Syndrome: A Randomized Trial.” Nutrition Journal. April 2011. https://nutritionj.biomedcentral.com/articles/10.1186/1475-2891-10-40.