Share on Pinterest New research suggests a vegan diet may outperform a Mediterranean diet when it comes to achieving short-term weight loss. Image: Claret Castell/Stocksy.
- Advanced glycation end products, generally found in higher amounts in animal foods, are harmful substances associated with insulin resistance and metabolic problems.
- A recent study shows that a low-fat vegan diet may be more effective at lowering AGE levels and controlling weight than the Mediterranean diet, at least in the short term.
- For people looking to try a low-fat vegan diet, experts recommend gradually incorporating more plant-based meals into their routine and seeking advice from a doctor or registered dietitian to ensure a balanced diet.
A recent study published in Limits in nutrition suggests that a 16-week low-fat vegan diet can significantly outperform a Mediterranean diet in reducing advanced glycation end products (AGEs) and promoting weight loss.
AGEs are harmful compounds that are generally present in foods cooked at high temperatures, especially those of animal origin rather than plant origin. They have been linked to insulin resistance, inflammation, and oxidative stress, potentially contributing to a variety of chronic diseases including diabetes and heart disease.
The new research is a secondary analysis of a 36-week crossover study conducted in 2019 by the Physicians Committee for Responsible Medicine that compared the weight loss and cardiometabolic health outcomes of a low-fat vegan diet with a Mediterranean diet.
The results of the current study showed significant reductions in dietary AGEs and body weight in participants on the low-fat vegan diet, while participants on the Mediterranean diet experienced no significant changes.The findings suggest that a low-fat vegan diet may have clear benefits in the short term. However, more research is needed to determine whether it is truly more effective than a Mediterranean diet for long-term weight loss and overall health.
The original trial included 62 overweight or obese adults aged 30 to 76 years, screened from a cohort of 506 people. Those who were already following a vegan or Mediterranean diet or had certain conditions or lifestyle factors that could affect the results were excluded.
Participants were randomly assigned to a low-fat vegan diet or a Mediterranean diet for 16 weeks without calorie restriction.
The low-fat vegan diet focused exclusively on plant foods, including fruits, vegetables, grains and legumes, and a daily supplement of 500 micrograms of vitamin B12. It excluded animal products and added fats.
The Mediterranean diet emphasized fruits, vegetables, legumes, and fish, along with 50 grams of extra virgin olive oil per day. It discouraged red and processed meat, cream, butter, margarine, sugary drinks, pastries, and processed snacks.
After the first 16 weeks, participants returned to their baseline (typical diet) diet for a 4-week "washout," before switching to the opposite diet for another 16 weeks.
During the free-living study, participants were asked to maintain consistent physical activity and medications unless otherwise directed by their physicians. They attended weekly classes on their assigned diet for nutrition education, recipes, meal plans, and group support.
The researchers monitored the participants' body weight and body shape, checked their adherence to their diets, and had registered dietitians review the participants' diet records at four points during the study over a three-day period.
In the secondary analysis, they analyzed dietary AGEs using the self-reported diet data from the original trial. Each food was assigned an AGE score based on a published database of AGE content, along with estimates for less than 10% of foods that were not in the database.
The Physicians Committee analysis found that there were significant differences in dietary AGEs and weight changes between a low-fat vegan diet and the Mediterranean diet.
The low-fat vegan diet resulted in a 73% reduction in dietary AGEs and an average weight loss of 6 pounds, while the Mediterranean diet produced no changes in AGE levels or body weight.According to the study authors, the reduction in dietary AGEs on the low-fat vegan diet was primarily due to eliminating meat (41%), minimizing added fats (27%), and avoiding dairy products (14%). These products are all known to be major sources of dietary AGEs.
The majority of weight loss on a vegan diet comes from losing body fat and visceral fat. These are ideal body composition changes to promote long-term health and reduce the risk of chronic disease.
Furthermore, changes in dietary AGEs were associated with changes in body weight. This association remained strong even after adjusting for total calorie intake.
When assessing the lack of effects of the Mediterranean diet, it is important to consider the characteristics of the study participants.The study authors noted that their participants were a "health-conscious group" with relatively low saturated fat intake.
This could explain the lack of results for the Mediterranean diet, in contrast to previous studies reporting benefits of the Mediterranean diet compared to other diets and in different populations, such as older adults and people with type 2 diabetes.
However, in support of the results, previous studies have reported that a low-fat vegan diet can lower dietary AGEs overweight adults And postmenopausal people compared to a typical diet.
Ultimately, this was a study that directly compared the Mediterranean diet to a low-fat vegan diet in reducing AGEs and associated body weight outcomes, and the authors considered it "hypothesis generating."
This, combined with the use of self-reported dietary data and other potential limitations of the study, suggests that more research is needed to confirm these new findings.
AGEs are complex compounds that form in the bloodstream when sugars react with proteins, fats, or nucleic acids - a process known as glycation.
Interestingly, AGEs also come from our food. Most AGEs in the body come from dietary sources and can build up to harmful levels with certain dietary and lifestyle habits.
"[AGEs] are especially abundant in animal products," which are typically high in protein and fat, "and in foods cooked at high temperatures, especially when gristle or charring develops," said Thomas M. Holland, MD, MS, a physician-scientist and assistant professor at the Rush Institute for Healthy Aging, Rush University Medical Center, who was not involved in the study. Medical news today.
Plant foods, on the other hand, generally have lower AGE content because they contain lower concentrations of proteins and fats and cooking temperatures are typically lower.
Holland explained how reducing AGEs in the diet, specifically by following a low-fat vegan diet, can help promote weight loss:
"The low-fat vegan diet, which excludes animal products, reduces fat intake, and avoids dairy, leads to a significant reduction in AGEs in the diet. This reduction is crucial because AGEs contribute to insulin resistance, which can hinder the body's ability to effectively manage glucose, leading to weight gain. By reducing AGEs, the body can better regulate insulin, reduce inflammation, and improve overall metabolism, all of which contribute to weight loss."
"The challenge with the low-fat vegan diet is its long-term sustainability," Holland said, noting that "the Mediterranean diet, on the other hand, is often praised for its balance and ease of integration into daily life, which may make it a more sustainable option for many people."
Still, he suggested that "although a vegan diet may seem restrictive at first," especially for those transitioning from a typical Western diet, "it actually offers a wide variety of foods that are often underutilized."
Eliza Whitaker, MS, RDN, a registered dietitian nutritionist at Dietitian Insights who was not involved in the study, agreed and offered advice for people looking to follow a low-fat vegan diet:
- include various fruits, starchy and non-starchy vegetables, beans, legumes, nuts, seeds, grains, and soy products.
- Limit processed foods and read nutrition labels on prepared vegan foods to watch your fat intake
- Take a vitamin B12 supplement and discuss with a healthcare provider whether you should supplement with iodine, vitamin D, and other essential vitamins and minerals
- Discover new spices or flavors to enhance vegan foods and create similar flavor profiles and textures to animal products
- Before adopting a healthy, low-fat vegan diet to control your weight, consult your doctor or a registered dietitian to determine if this is the best approach to weight loss for you.
Both experts recommend taking a gradual approach that works for you, based on what feels most sustainable for you. This could mean introducing a few low-fat vegan meals into your weekly diet and stopping there, or, if you prefer, eventually eliminating animal products altogether.
"Even if a vegan diet isn't for you, this study provides additional evidence to support reducing consumption of animal foods and increasing consumption of plant foods," Whitaker concluded.
