A number of years ago, a colleague of mine tried a high-protein diet for weight loss because he’d met someone special in another state on an online dating site — only he’d posted pictures of himself when he was 30 to 40 pounds lighter.
Unfortunately, a regular meal schedule is a luxury few doctors get. Most physicians eat on the run when there’s an opening in their schedule, which often leads to weight gain from poor food choices.
My colleague’s interstate romance grew through correspondences, and he agreed to travel to the woman’s hometown for a meeting. The only trouble was that he wanted to lose weight quickly.
Like many others, he started a high-protein, low carbohydrate diet; his consisted almost entirely of animal proteins, along with a few strawberries. More than 80 percent of his diet came from animal proteins.
I’m happy to report that he lost the desired weight, and the online romance ended in marriage.
Should You Try a High-Protein Diet?
Many people use high-protein diets such as Weight Watchers or the South Beach Diet, among others, to quickly lose weight. And once they reach a certain weight goal, many will transition to a more balanced diet.
But some people stay on a diet long term to maintain their weight loss. And weight loss through diet certainly has significant benefits, including lowering your risk of developing high blood pressure, heart disease, diabetes, some cancers, and sleep apnea.
Numerous high-protein diets are available: When I searched for new books on the topic, the online bookstore yielded more than 100 options.
Most people I ask about a high-protein diet think of eating more meat and eggs. But protein is abundant in many other food sources.
Animal products high in protein include most forms of meat, eggs, seafood, dairy, cheeses, and whey protein.
Plant products high in protein include beans and legumes, such as lentils, chickpeas, soybeans, and black-eyed peas — also known as pulses. Other plants that contain protein include some vegetables (broccoli and spinach, for example), most nuts (like almonds, cashews, pistachios, and many nut butters), and seeds like chia, sunflower, poppy, quinoa, and many more.
Why Food Sources Matter in a High-Protein Diet
Given these facts about protein, here are two questions you may want to ask yourself before you embark on a high-protein diet:
- Is the high-protein diet a healthy long-term option?
- Should you switch from animal-based proteins to plant-based proteins in your diet?
A study published in October 2016 in JAMA Internal Medicine shed some light on these questions as they related to long-term risk of death from heart disease and cancer.
The study included 131,342 participants, of whom 85,013 were women; the average age was 49. These people were evaluated every two years with regard to their lifestyle and diet, and they were followed for more than 20 years.
Researchers compared people in groups based on the percent of protein in their daily diets:
- Animal protein (less than 10 percent, 12 to 15 percent, or greater than 18 percent)
- Plant protein (less than 3 percent, 4 to 5 percent, or more than 6 percent)
The study participants were not assigned to a particular diet, but instead reported on what they chose to eat. This study’s findings reflected broad dietary patterns and various protein sources:
- For each 10 percent increase of dietary animal protein, participants had an 8 percent increase in risk for heart disease-related death.
- For each 3 percent increase in dietary plant protein, participants had a 12 percent decrease in heart disease-related death.
The people who reported high levels of animal protein consumption and were most at risk for death from heart disease were also overweight, more sedentary, consumed alcohol, or smoked.
The Health Advantages of Plant-Based Proteins
If plant proteins are healthier, what happens when you substitute plant protein for animal protein in your diet?
Researchers found that for every 3 percent substitution of plant proteins in place of animal protein, there was a 34 percent reduction in mortality (risk of death) from heart disease. These benefits were seen in both active and inactive people. The best animal protein source to swap for a healthier plant protein source, according to this study, was processed red meat.
And for every 3 percent substitution of plant protein in place of animal protein, cancer-related death in study participants dropped by 17 percent. In this analysis, the best animal protein sources to swap for plant proteins were, again, processed red meat products — but also eggs.
High-Protein Diets Preserve Muscle Mass
A second, smaller study published in October 2016 in Cell Reports highlights the need to consider transitioning to a well-rounded diet once you’ve achieved your desired weight loss goal.
A healthy diet is primarily derived from fruits, nuts, vegetables, and very few processed foods. In this study of postmenopausal women who had developed prediabetes, researchers looked at the influence of a high-protein diet on glucose (sugar) levels.
Approximately 60 women with prediabetes participated and were assigned to a low-calorie, rapid weight loss diet or a high-protein weight loss diet. Both diets resulted in a loss of 8 to 10 percent of body weight.
But women who followed a high-protein diet preserved much more lean muscle mass. Essentially, most of their weight loss was loss of fatty tissue. One caveat: Their high-protein diet did very little to improve their muscles’ natural sugar intake, so some of the prediabetes condition persisted.
Small Diet Changes, Big Health Benefits
If you get your protein from animal sources like meat, eggs, and dairy, the first study is great news. When you make small changes to your diet and swap out some of the animal products for plant protein, you may get a tremendous benefit in lowering your risk of death from heart disease and cancer. These health dividends were observed when people substituted plants for animal products in just 3 percent of the diet. Few other things you can do will pay off so well.
If you keep a diary of your daily diet over a week, you should be able to find a few animal protein sources to eliminate; in particular, it’s helpful to substitute plant-based proteins for processed red meats.
You may not be considering a diet change to prepare for the love of your life like my colleague, but when you look at the evidence, it seems most of us could use more plant protein in our diets.
Photo: Carlo A/Getty Images; Getty Images