While you can definitely gain weight as a vegan by eating too much junk food (there’s a lot of vegan junk these days), vegans are thinner than meat eaters in general.
Quite a few studies have confirmed this, I’ll go over a few in this post just so you know the significance of the difference.
We’ll also look at why there is a difference.
Study 1: BMIs of 60,000+ People in North America
This first study was based on self-reported data from members of the Seventh-Day Adventist church members in North America.
They looked at the mean body mass index (BMI) for multiple types of diet groups. Here were the average BMI in each group:
- Vegans (23.6 kg/m2)
- Lacto-ovo vegetarians (25.7 kg/m2)
- Pesco-vegetarians (26.3 kg/m2)
- Semi-vegetarians (27.3 kg/m2)
- Non-vegetarians, or meat-eaters (28.8 kg/m2)
On average, vegans were 5.2 kg/m2 lighter. It’s pretty safe to assume that for the average person, that weight will be mostly fat.
For reference, someone who is 180 cm tall would be:
- 76.5 kg (168.6 lb) @ 23.6 kg/m2
- 93.3 kg (205.7 lb) @ 23.6 kg/m2
So it’s quite a big difference.
Study 2: EPIC-Oxford Study of BMI
EPIC-Oxford is a huge collection of data in England that began in 1993.
This study is one of many that have looked at specific parts of the EPIC-Oxford dataset, and it looks at BMI.
Similar to the first study above, here’s what they found when it came to BMI:
- Vegans (22.49 kg/m2 in men, 21.98 kg/m2 in women)
- Meat eaters (24.41 kg/m2 in men, 23.52 kg/m2 in women)
Again, vegetarians were somewhere in-between.
Note that these values have been controlled for age, since vegan demographics skew younger.
The BMIs are lower across the board, but that’s just due to North Americans being bigger than the British I’d imagine.
The more important thing is that the trend is the same.
Other studies show the same trend, I’m not going to go over them all here, it’s redundant.
In summary: It’s pretty safe to conclude that vegans are NOT fatter than meat eaters according to these studies.
But this second study also tried to look at why vegans are skinnier, so let me go over those quickly.
There were multiple significant correlations, but the most important were:
- High protein
- Low fibre intake
- Lifestyle factors (e.g. smoking, physical activity, education level) – less than 5%
The majority of the BMI difference was explained by the fact that vegan diets are generally lower in protein and higher in fibre.
Remember that these are just correlations, so they don’t give us all the answers.
For example, does a meal high in fiber tend to have fewer calories, or do we eat less of it because fiber is more filling? That would be something that needs to be tested by itself.
Summary: Vegans Are Generally Thinner Than Meat Eaters
According to the data, the average vegan has a much lower BMI than the average meat eater.
There are of course exceptions when you look at athletes, but when you ask a question like this, you’re looking at the general population.
Overall, studies so far show that vegans are not only healthy, but likely healthier than most omnivores.