Weight management can be an uphill battle involving counting calories, with people eagerly watching and hoping for results that will encourage them. A clinical trial suggests a way to see quick weight loss by exchanging a diet that includes some high-acid producing foods for a diet comprised solely of low-acid producing foods.
The result was a 13-pound weight loss in participants over a 16 week period, which is quick but not so quick that doctors consider it unhealthy. The finding is the latest within the body of research that links eating low-acid-producing foods to positive health effects and high-acid-producing foods to adverse health effects.
Low-Dietary Acid Load and Weight Loss
According to the authors of the clinical trial published in Frontiers in Nutrition, protein and phosphorus found in certain grains, meat, cheese, fish, and eggs release acid precursors, which produce an acidizing effect on blood pH, so an eating plan rich in these foods has a high-acid dietary load. Conversely, most fruits and vegetables have an alkalinizing effect, even if they contain acid, so an eating plan that features these foods prominently has a low-acid dietary load.
The authors of the clinical trial explored how changing dietary acid load from the two diets might affect weight. They randomized 62 overweight adults to either a low-fat vegan diet or a Mediterranean diet for 16 weeks. Following a four-week washout, the participants were put on the other diet for another 16 weeks.
In addition to recording weight loss, the authors calculated the acid load of the diets through net endogenous acid production (NEAP) and potential renal acid load (PRAL). PRAL estimates the impact of foods on pH based on levels of magnesium, protein, potassium, calcium, and phosphorus, while the NEAP further modifies the score for a person’s height and weight.
Results showed that acid load decreased significantly on the vegan diet but not on the Mediterranean diet. The vegan diet was also associated with a weight loss of 13.2 pounds, while no weight change occurred on the Mediterranean diet. The authors cited an earlier study that indicated the connection between vegan diets and weight loss is independent of calorie intake, meaning that, despite that vegan diets tend to be low in calories, other factors besides that play a role.
Since a vegan diet consists of plant foods and excludes animal foods, it is highly alkalinizing. Although the Mediterranean diet focuses on plant foods, it also includes fish and some dairy and poultry, so it is not as alkalinizing as the vegan diet.
“Eating acid-producing foods like meat, eggs, and dairy can increase the dietary acid load, or the amount of acids consumed, causing inflammation linked to weight gain,” lead author, Dr. Hana Kahleova, director of clinical research at the Physicians Committee, said in a press statement. “But replacing animal products with plant-based foods like leafy greens, berries, and legumes can help promote weight loss and create a healthy gut microbiome.”
Muscle Wasting
The vegan diet provided enough protein from plant sources, such as beans, lentils, peas, soybeans, tofu, and soymilk, Kahleova told The Epoch Times in an email. In addressing a question about the possibility of muscle wasting when on the vegan diet, she related that the research team measured body composition, using a DXA or bone-density scan, and most of the weight loss was due to fat loss.
One concern about following a diet that excludes animal foods is developing a vitamin B12 deficiency. “This was provided in a supplement,” Kahleova said. “Vitamin B12 can be consumed in nutritional yeast, fortified cereals, and plant-based milks, etc., but the easiest way to make sure we get enough of it is to take a supplement.”
“The alkalizing component of the low-acid diet appears to unlock metabolic benefits beyond calorie restriction, and that’s powerful,” Dr. Hector Perez, lead bariatric surgeon at Renew Bariatrics, who was not involved in the study, told The Epoch Times in an email.
A low-acid vegan diet can be an effective, intelligent strategy for weight loss, but only when it’s mindfully fortified and personalized, Perez said. Vegan diets, if not well planned, can fall short in B12, iron, calcium, omega-3s, and protein quality, which are especially critical when you’re already losing weight or lean mass, he said.
High-Protein Diet and Weight Loss
Some studies indicate that eating more than the recommended daily allowance (RDA) of protein is associated with weight loss. For instance, a study published in the Journal of Obesity & Metabolic Syndrome found that high-protein diets are effective for weight loss and work by decreasing hunger hormones and increasing satiety hormones. However, other research indicates that high-protein diets aren’t advisable for people with impaired kidney function, as they are associated with a higher death rate.
The two experts below recommend the high-protein diet for weight loss if certain conditions are met to ensure its safety. One advises going significantly above the RDA of protein, while the other advises going only slightly above the RDA.
25 to 50 Percent Above Protein RDA
Perez recommends the high-protein diet for weight loss, but said “the devil is in the details.” Loading up on ribeye steaks and protein shakes isn’t a free pass because protein should be paired with fiber and healthy fats, and it’s important to always keep an eye on kidney function and hydration.
“The current RDA for protein is 0.8 grams (g) per kilogram (kg) of body weight, but that is the minimum to prevent deficiency, not the optimal amount for preserving muscle during weight loss,” he said. “I suggest 1.0 to 1.2 g/kg, which is about 25–50 percent above the RDA. For a 70 kg person, we’re talking around 70 to 84 grams daily instead of the baseline 56 grams.”
Of note, one cup of chopped chicken breast contains 43 grams of protein.
Protein shouldn’t crowd out fruits and vegetables, Perez noted. He recommends making protein the anchor of meals and loading the rest of the plate with high-fiber plants.
A Little Above Protein RDA
While weight management is extremely important, it should be viewed within the context of total health. A weight-loss strategy, such as the high-protein diet, may not provide the nutrients needed for many other aspects of health if it’s taken too far, according to Lisa Schultz, a certified nutritionist.
High-protein diets can support weight loss, but the conversation is often oversimplified, Schultz told The Epoch Times in an email. Protein is important because it has functions that can indirectly help with weight management, but eating a high-protein diet without considering the quality or the balance of fiber, healthy fats, and carbs can backfire.
“I’ve seen people load up on protein shakes and processed meat while ignoring vegetables and complex carbs, so they end up feeling tired, bloated, or stuck,” she said.
Schultz recommends going a little over the RDA of protein. The real key is a balanced plate: lean proteins paired with plenty of fiber-rich vegetables and whole grains, which not only supports weight loss but also improves digestion, energy, and mood. Protein matters, but it’s just one piece of the puzzle, she added.
Other Health Effects of Dietary Acid Load
Research shows that dietary acid load can influence the following:
Cancer
High-acid load diets may link to a higher risk of cancer and a poor prognosis when cancer is already present, according to a systematic review published in Frontiers in Nutrition. Underlying mechanisms may include the fact that acid-producing diets are usually low in fruits and vegetables but high in animal and processed foods, which are linked to cancer. Acid-base imbalances also regulate certain molecular activities that may be associated with cancer occurrence and progression.
Type 2 Diabetes
A French population-based study published in Diabetologia found that a high-acid load from the Western diet was associated with an increased risk of Type 2 diabetes, independent of other risk factors for the disease. If the results are verified in future studies, it may lead to the promotion of diets with a low-acid load to prevent diabetes, the authors said. The underlying mechanisms may be that diets with high acid loads promote insulin resistance and reduced insulin sensitivity, which are both indicators of poor blood glucose control.
Mental Health
A study published in BMC Psychiatry found that diets with a high-acid load were linked to a higher incidence of anxiety in Iranian men and women exposed to the highest levels of acid, as well as a higher incidence of depression in women. The mechanism responsible may involve acid-sensing ion channels that are sensitive to extracellular acidity changes. A diet with a high-acid load may activate the channels, which animal studies show may be associated with biological changes that contribute to depression.
Acid-Alkaline Diet Controversy Explained
Some members of the medical community ascribe to the acid-alkaline diet theory, while others don’t. When the views of the two camps are analyzed, the differences aren’t as great as one may presume.
The controversy seems to stem from two factors. One is confusion about eating foods that contain acid versus eating foods that increase dietary acid load. Acid load denotes how foods affect pH after digestion and metabolism. Fruits that contain acid, such as oranges and tomatoes, have an alkalinizing effect on the body following digestion, so they are considered to have a low-acid dietary load. Foods with a high-acid dietary acid load, such as meat and eggs, are those that have an acidic effect on the body following metabolism, according to a research article published in Open Heart.
The other factor contributing to the controversy involves the distinction between low-grade metabolic acidosis and true acidosis. People who believe in the acid-alkaline food theory assert that low-grade metabolic acidosis is a condition that affects many people in Western countries who eat diets that are high in meat and low in fruits and vegetables, according to the authors.
Those who do not believe in the acid-alkaline food theory contend that acid load from food cannot put a person in acidosis because of the body’s buffering systems that maintain a normal pH range between 7.35 and 7.45. They are correct in that food won’t put the pH below 7.35, which is true acidosis and a medical emergency.
People in the acid-alkaline food camp agree that food won’t cause true acidosis, but they believe food with a high acidic load can cause low-grade metabolic acidosis, which they define as pH that is in the lower range of normal. The article designates this as being higher than 7.35 and lower than 7.42.
Kahleova is an expert in the acid-alkaline food camp. Eating foods that increase dietary acid load leads to a low-grade metabolic acidosis and triggers the release of the stress hormone cortisol, which is associated with adverse health effects, she said.
Plant foods, on the other hand, not only keep the pH from going in the direction of a low-grade metabolic acidosis but also reduce the production of cortisol. These effects promote weight loss and other markers of cardiometabolic health.
“The idea of low-grade metabolic acidosis from dietary choices refers to small, chronic increases in the body’s acid load, not a dangerous drop in blood pH,” Dr. Asim Cheema, an internal medicine and cardiology specialist at Your Doctors Online, told The Epoch Times. This concurs with the view of experts like Kahleova.
However, high acid-load diets may not directly affect blood pH, but they can strain the kidneys and bones over time, Cheema said. Low-grade acidosis is subtle and long-term, potentially affecting bone density, muscle function, and inflammation markers. “So, while ‘alkaline’ foods may not make your blood more alkaline, a plant-rich diet still supports health by lowering inflammatory burden and supporting metabolic processes, even if the mechanism isn’t via blood pH.”
In summary, people in the acid-alkaline food camp believe that plant foods produce health benefits by lowering pH a tiny bit, even though it is still within the normal range. In contrast, those who don’t believe in the acid-alkaline food theory believe that the benefits from plant foods stem from their anti-inflammatory or other health-promoting properties.
The bottom line is that whichever group is correct, eating a diet that includes plenty of fruits and vegetables is extremely health-promoting.
