Nearly 42% of American adults suffers from obesity, according to the latest numbers from the Centers for Disease Control and Prevention (CDC).
In 1971, cardiologist Dr. Robert Atkins released The Atkins Diet Revolution, introducing the general public to a revolutionary high-protein, low-carbohydrate diet plan and creating decades of debate within the medical and nutritional communities. Under the Atkins diet plan, portioned-controlled salads and an emphasis on the food pyramid gave way to almost limitless amounts of fatty meats, dairy products, and other formerly restricted food choices.
Subsequent high-protein diets such as The Zone or Keto further refined the fat-burning principles behind Atkins approach, with the ultimate goal of inducing a fat-burning metabolic state called ketosis. The radical dietary steps required to induce and maintain ketosis have raised concerns in the medical community, but many dieticians would agree that high-protein diet plans have indeed contributed to weight loss and overall health improvement.
High Protein Diets Really Do Change Body Chemistry
The actual mechanics of high-protein diets such as Atkins still remain largely a mystery to researchers. It was originally believed that protein-rich foods took longer to digest than foods higher in carbohydrates, such as breads or cereals. Subsequent weight loss was attributed to a greater sense of fullness between meals. Inducing ketosis may have helped burn body fat during a starvation response, but it was not a long-term solution to weight loss.
In a 2016 study presented at the Society for Endocrinology annual conference in Brighton, England, researchers released laboratory testing results on rodents fed high-protein diets. They discovered that phenylalanine, a common byproduct of protein-rich diets, interacted with the body's calcium-sensing receptor (CaSR). This receptor triggers the release of GLP-1, a hormone responsible for appetite suppression. Higher levels of GLP-1 and lower levels of ghrelin, a hunger-inducing hormone, led to long-term, sustainable weight loss.
“Our work is the first to demonstrate that activating CaSR can suppress appetite,” said the study's lead author, Mariana Norton. “It highlights the potential use of phenylalanine or other molecules which stimulate CaSR – like drugs or food components – to prevent or treat obesity.”
Further research into the effects of GLP-1 has led to the development of new injectable medications for both type 2 diabetes and weight loss.
Ketosis Really Does Trigger Weight Loss
Carbohydrates in the form of glucose are the usual energy source for the human body throughout the day. Excess glucose, however, is stored in fat cells, contributing to obesity. The body will only use these fat cells as an emergency energy source if glucose supplies become depleted from a lack of carbohydrates. At this point, the body shifts to a starvation mode known as ketosis. The release of ketones enables the conversion of fat cells into energy, and one of the side effects is weight loss.
Many medical professionals and dieticians do not consider ketosis a healthy state of being for the long term, but short-term high-protein diets for temporary weight loss are actually effective. Once carbohydrate levels are restored through diet modification, the body returns to a glucose-based metabolism.
High Protein Foods Really Do Curb Hunger
There are other diet and health issues that directly benefit from a high-protein diet plan, or at least the suggested list of high-protein foods. Within the carbohydrate/fat/protein triangle, proteins take the most time to metabolize, creating a longer sense of fullness while reducing levels of the hunger-inducing hormone ghrelin.
Protein-rich foods have also been shown to improve muscle mass and bone strength. A pervasive myth concerning the calcium-leaching effects of a high-protein diet has also been disproven. A higher protein diet, even if not a defined “high-protein diet,” helps maintain bone strength into the age where osteoporosis in women becomes a significant health concern.
Studies also suggest a connection between a high-protein diet and lower blood pressure. Protein also reduces the levels of unhealthy LDL cholesterol and triglycerides, which improves overall cardiovascular health.
Potential Risks of High-Protein Diets
While many high-protein, low-carb diets have successfully shifted from trendy fads to established food plans, there are still some potential risks participants should consider. The metabolic state of ketosis, the basis for many of these plans, creates a significant workload for the kidneys and liver. Dieters with known kidney or other metabolic conditions should seek medical advice before participating in a restrictive high-protein diet plan.
One common side effect of many high-protein diets is constipation, largely due to the slower processing of proteins during digestion. Dehydration, another well-known side effect, also contributes to this digestive issue.
Other potential side effects of high-protein diets include bad breath, irritability, and a general reduction in energy.
Overall, it's important to talk to a physician before making a major change to your diet.