A new study has revealed that a low-fat, plant-based diet may be more effective for weight loss than popular weight-loss injections such as Ozempic and Wegovi, which are considered a revolution in the fight against obesity.
In a study of 224 overweight adults, researchers found that people who switched from a meat- and fish-based diet to a low-fat, plant-based diet were able to lose 5.9 kilograms in just four months.
The findings were published in the journal JAMA Network Open, where researchers described a low-fat plant-based diet as "an effective tool for reducing body weight."
In contrast, other studies have shown that weight-loss injections produce less effective results in the same timeframe. A study published in The Lancet Diabetes & Endocrinology found that participants who received a weekly injection of semaglutide (the active ingredient in Ozempic and Wegovi) at a dose of 2 mg lost 6.9 kg over nine months, just 1 kg less than those on a vegetarian diet, and in more than twice the duration. Those using the lower dose (1.0 mg) lost only 6 kg in the same period.
The researchers attribute the effectiveness of a plant-based diet to its ability to reduce daily calorie intake by approximately 500 calories, leading to significant weight loss. They divided participants into two groups: one followed a plant-based diet, while the other maintained their usual eating habits. The plant-based group was permitted to consume unlimited quantities of fruits, vegetables, grains, and legumes, while avoiding meat, fish, dairy products, and eggs.
After 16 weeks, the plant group's consumption of vegetables increased by about 150 grams per day (the weight of a medium sweet potato), and of fruits by about 80 grams (about a kiwi), and their consumption of legumes tripled, as did plant-based meat alternatives.
The study concluded that a low-fat vegetarian diet reduces weight by lowering calories, making it "an effective treatment for overweight adults."
In a secondary analysis, the researchers explained that diets high in meat cause obesity because they contain more calories. Vegetarian participants consumed similar amounts of food by weight, but their daily calorie intake decreased from 1,834 to 1,343 calories—more than a quarter less. According to the experts, this is because plant-based foods are high in water and fiber and low in fat, increasing food volume without increasing calories and promoting satiety without deliberate restriction.
However, the researchers pointed out that the study relied on participants' self-reporting of their food intake, which could affect the accuracy of the results. Nutrition experts also warn that an improperly planned vegetarian diet can lead to deficiencies in essential nutrients such as calcium, iron, and vitamin B12.
