Wednesday marks World Food Day. The theme for this year is: healthy diets for a zero hunger world. The theme calls for action across sectors to make healthy and sustainable diets affordable and accessible to everyone.

Hunger and obesity are coexisting in today's world. Data from the Food and Agriculture Organization shows that while 820 million people are suffering from hunger, even more have weight and obesity issues.

Over 670 million adults and 120 million children between five and 19 years old are obese. An estimated two trillion U.S. dollars is spent each year to treat obesity-related health issues.

Unhealthy diets, together with sedentary lifestyles, have overtaken smoking as the No. 1 risk factor for disability and death.

Trudy Wijnhoven, the nutrition officer at the UN Food and Agriculture Organization, explained why hunger and obesity coexist does at the same time. Obviously, there are many reasons.

"Nowadays, among the leading cause of the disease is a disability, you see some people not eating sufficient food provided calorie and others. But other people are eating far more food than necessary. Poor diet and unhealthy food which is leading you [to] eating some suffusion food provide," said Wijnhoven.

"Poor family poor communities are not always affordable or accessible. Some of them have real little income, then they may compromise on the quality. So what can be done that not on one common solution that man stable looking for each one should be addressed," said Wijnhoven.

"Government can put policies on that. Food should easy to choose. Consumer should get good conditionally make the right food for choice."

As people's awareness of healthy eating is rising, the business community, by definition, plays an important role in this campaign. As you mention, the man is calling for more involve like government, consumers and business community.

"In general, we have said food companies and manufacturing continue to develop and provide affordably. Manufacturing continues to develop. We need to face out promoting food behind fate, sugar, and salt. And all the marketing should receive other lessons. Farming business needs to be committed to considering agriculture can produce a serious variety of food and vegetables."

A recent study said that red or processed meat is not necessarily bad for one's health. The report says the evidence is weak, and any risk to people's health is small.

Wijnhoven also added, "what is a healthy diet? Basically, it's one that meets the nutritional needs of individuals to lead an active life and reduce the risk of disease. It includes, among others, fruit, vegetables, legumes, nuts, seeds and whole grains, and foods that are low in fats, sugar, and salt. But some of the consensuses about what's good for our bodies is being updated or challenged."

And with the popularity of social media, many key opinion leaders are advocating a variety of diets that they claim can work magic. They have generated millions of followers, bringing lucrative businesses. However, some of the popular vegan bloggers have reported health issues and returned to meat recently.