The difference in life expectancy between the USA (where beef is heavily consumed) and India (where you may get lynched on suspicion of eating it) is 78.39 - 72 = 6.39 years at birth.
Most people attribute this difference to the GDP/capita ($89,600 vs. $12,132 PPP) or the number of doctors per capita (36.082 vs. 7.265 per 10k), not the diet.
At the risk of stating the obvious, meat is not the only difference in diet.
But agreed that diet is also not the only link to longevity. Although a Mediterranean diet is higher on plant based foods, considered healthier, and those countries do have better life expectancy than USA.
This stands against the evidence. Beef is causally linked with the largest killers of Americans, including heart diabetes, diabetes, and obesity in general. "a mostly plant-based diet could prevent approximately 11 million deaths per year globally, and could sustainably produce enough food for the planet’s growing population without further damage to the environment."
A "Mediterranean diet" is more healthy than the average American diet because it is more plant-based.
https://www.sciencedirect.com/science/article/abs/pii/S01406...https://www.health.harvard.edu/blog/with-a-little-planning-v...
