"The only way to keep your health is to eat what you don't want, drink what you don't like, and do what you'd druther not.” If only the answer to the world’s health concerns were as simple as Mark Twain quipped.

From eradicating polio to addressing antimicrobial resistance and providing universal health coverage, healthcare leaders will have a packed agenda when they meet for the 72nd World Health Assembly this week in Geneva.

As the world's healthcare community gathers from the 20th to the 28th of May, here are five things you might not know about health challenges around the globe.

1. Obesity is a big problem

Most of us live in countries where obesity is a bigger cause of death than being underweight. About 13% of the world’s population was obese in 2016, despite the condition being largely preventable. And in many low- and middle-income countries, obesity and malnutrition exist side-by-side, sometimes within the same community or household.

2. Less wealthy nations are losing out

Almost $160 billion a year is spent on health research and development, according to a report from the Brookings Institution, but just a fraction of that goes to the developing world.

Creating medicines for a diverse range of tropical illnesses that primarily affect populations in very poor nations - a concept known as neglected disease R&D - is particularly underfunded.

The costs of drug development, combined with regulatory hurdles and governance challenges in some countries all contribute to lower investment for improving the health of patients in low- and middle-income nations.

Trends in the total annual number of US deaths caused by cardiovascular disease according to gender
Trends in the total annual number of US deaths caused by cardiovascular disease according to gender
Image: AHA Journals

3. The world’s biggest killer strikes more women than men

Cardiovascular disease is the biggest cause of death worldwide, but our understanding and treatment of it is almost entirely based on men. Although heart disease is more prevalent in men, a greater number of women are killed by it, studies have shown. Women are more likely to have symptoms different than the dominant male-based criteria for diagnoses, and so heart illness in women more frequently goes undetected.

Image: World Health Organization

4. Every 25 seconds, someone dies on our roads

Almost 4,000 people are killed on the world’s roads every day. More than half of these deaths happen to people with the least physical protection – motorcyclists, cyclists and pedestrians. It's especially a problem in India, which has the highest number of scooters, mopeds and motorcycles in the world.

5. Africa has access to a tiny proportion of the world’s healthcare workers

The global disease burden is heavily tilted towards Africa, but the continent only has access to 3% of the world’s health workers, and limited access to global financial resources. The distribution of medical professionals across the world is uneven, with many of the countries with the lowest disease burdens enjoying the largest health workforces. Relative to the size of its population, Cuba has the highest number of doctors worldwide.