Vegetables Preventing Obesity?

Obesity is a global issue impacting the lives of adults and children, with an estimated 67% of American adults [1] and 10% of children worldwide being overweight or obese [1]. The significant health risk of obesity highlights the importance of prevention methods.

The article "Vegetarian diets and childhood obesity prevention" [1] analysed the relationship between vegetarian diets and obesity.

This paper mentions results displaying that vegetarians had an average Body Mass Index (BMI) of 22.1 and 25 for non-vegetarians [1]. However, the paper does not state what these non-vegetarian diets are, which could impact assessing what exact diets cause this difference. Furthermore, BMI has limitations, as according to BMI calculators, a BMI of 22.1 is healthy while a BMI of 25 is overweight. However, this would classify a person who is 6 feet tall and 82 kg as overweight. For many people, this would not be unhealthy. 

Vegetarianism and Weight in Adults.

In addition, throughout 50 studies [1], there were no significant differences in height between vegetarian and non-vegetarian men and women [1]. However, the paper shows that women vegetarians weighed 3.3 kg less than non-vegetarians on average [1], and male vegetarians weighed 7.6 kg less than non-vegetarians [1]. 

For greater insight, two studies were conducted on one of America's largest vegetarian communities, the Adventists [1], a religious group. They found that vegetarians had lower BMIs and gradually progressed as meat consumption increased (Figure 1) [1]. Furthermore, vegetarians were leaner than non-vegetarians (Figure 1) [1] and had a lower prevalence of obesity [1].

Fig. 1. The above table displays the Mean (average) BMI from a study on the Adventist community in 2002. It exhibits the mean BMI from each diet group in the study.

According to these results (Figure 1), only vegans had a healthy BMI, with all other diets identifying as overweight. This displays the limitations of solely using BMI to determine health status. 

Nevertheless, studies on regular populations from Oxford, the European Prospective Investigation into Cancer and Nutrition, and Germany supported these results [1], suggesting that low meat consumption may have an impact. The Oxford study displayed that non-vegetarians consumed less fibre, more alcohol, and more animal fat [1]; however, all these studies state that lifestyle made a minimal difference [1]. 

Solving Obesity in Children?

There is less known about the effects on children [1]; however, a study in the 1970s and 1980s showed that vegetarian children were leaner than non-vegetarian children [1]. However, some vegetarian diets led to compromised height [1].

Multiple studies show that children who were vegetarians weighed less than their non-vegetarian peers [1] and had a significantly lower BMI [1]. However, one study on white catholic children aged 7–18 found that vegetarians were taller than omnivores by 2.5cm in boys and 2cm in girls [1].

An additional study found that vegetarian girls aged 11–12 were 3cm shorter and hit their growth spurt and puberty one year later on average compared to public schools [1]. 

Different Definitions.

However, in one of these studies, vegetarians were defined as consuming meat less than once per week [1]. This variation in definitions across various papers could affect collaboration with other studies.

Preventing Cardiovascular Disease.

In addition, two studies found that vegetarian students had lower waist circumference and cholesterol levels than omnivore children [1]. These measurements indicate a lower risk of cardiovascular disease. Exercise was not associated with any of these measurements, suggesting that a plant-based diet may have a direct influence [1]. 

What Foods Contribute to This?

The paper also conducted a study that showed animal products such as meat, milk, and eggs were associated with an increased risk of being overweight in school-aged children [1]. However, plant foods were either protective (cereals, nuts, and legumes) or showed no association (fruits, vegetables, and plant protein products such as soy and tofu) [1]. However, this paper does not mention how much more likely one diet is to lead to being overweight or whether being overweight is determined by BMI.

The Three Main Takeaways

The paper believes in three main reasons why BMI is different between vegetarians and non-vegetarians [1]:

• Excluding meat that includes saturated fats and higher calorie density [1]. 
• Other lifestyle factors include smoking, physical activity, and education level [1]. 
• A variety of plant foods in a plant-based diet would be essential in preventing overweight and obesity and maintaining a healthy weight [1].

However, from the time of this study, it is uncertain whether avoiding meat or eating a more plant-based diet causes these effects [1]. 

Thus, vegetarian diets show promise for future prevention and mitigation methods to solve the obesity pandemic.

 A reminder that THIS ARTICLE IS NOT MEDICAL ADVICE, and it is vital to speak to your doctor before making any changes to a diet.

References

Reference paper “Vegetarian diets and childhood obesity prevention”

1.       Sabaté, J. and Wien, M., 2010. Vegetarian diets and childhood obesity prevention. The American journal of clinical nutrition, 91(5), pp.1525S-1529S.