> people from the Southern Hemisphere have a lower caloric intake

Do you have a source for this claim? In America, while not in the Southern Hemisphere, the CDC's Obesity Prevalence maps [1] show that obesity is concentrated in the southern states.

2017 Fattest Cities in America [2]: 1. Houston 4. Memphis 5. Tampa 6. Las Vegas 7. El Paso 9. Los Angeles 11. Tulsa 12. Miami

[1] https://www.vox.com/2014/11/17/7230641/maps-charts-obesity-w...

[2] https://www.mensfitness.com/weight-loss/burn-fat-fast/the-fi...