Bone-thin, malnourished kids in the developing world staring blankly into the camera have become the poster children of nearly every campaign to end world hunger. Yet despite evidence suggesting enough food is produced to feed every mouth on the planet, that global struggle persists.

More than 20 million people in Somalia, South Sudan, Nigeria and Yemen risk death by starvation by July, the United Nations warned in February. South Sudan has already declared a state of famine in a crisis largely due to a violent civil war.

But fighting global hunger is just one of the many complex challenges under food security.

From transboundary diseases affecting plants and animals to climate change to protectionist trade policies, the threats are diverse and plenty. Meanwhile, the demand for food continues to swell with global population projected to grow by another 2 billion by 2020.

Against this dreary backdrop, governments, multinational corporations and start-ups are looking to innovation and investments for solutions.

Singapore was ranked the third most food-secure country after the U.S. and Ireland on the Economist Intelligence Unit’s 2016 Global Food Security Index, which measures the affordability, availability, quality and safety of food across 113 countries.

It was a remarkable feat for the island-nation, smaller than New York City, to be ranked higher on the index than food-producing neighbors like Malaysia and Thailand.

Instead of looking to become food self-sufficient, the land-scarce country embarked on a comprehensive food security road map in 2013, which included a commitment to food innovation and to diversify food import sources.

The EIU index also revealed that Singapore’s agricultural tariff rates at 1.1 percent were the lowest in the world, underpinning the affordability of food in a country heavily dependent on food imports.

Singapore’s government agency, Agri-Food and Veterinary Authority (AVA), also supports its local farmers through productivity funding schemes and has agrotechnology parks, which support local farms with the infrastructure for advanced technologies and techniques.

Over in China, Beijing has rolled out drastic agriculture reforms to protect food security, such as the introduction of tax on fertilizers and pesticides and incentives for domestic farmers to grow crops in a sustainable manner.

Recent Chinese acquisitions also reflect the country’s food security priorities, from the controversial purchase of Australia’s largest dairy farm, Tasmanian Land Company, to a 50 percent stake in Silver Fern Farms, which is New Zealand’s largest meat processor.

The Agricultural Development Bank of China, which is one of the country’s main policy lenders, also agreed last year to invest up to 3 trillion yuan ($450 billion) by 2020 to modernize China’s agriculture industry.

In a bid to combat malnutrition and “hidden hunger” — which occurs when the quality of food people eat does not meet their nutrient requirements — one Singapore-based start-up hoped that a simple yet innovative solution might be found in a staple food.

Two years ago, news reports uncovered the poor quality and nutrition of catered meals for foreign construction workers in Singapore, which gave Jack Sim the idea for a social enterprise to provide fortified rice.

Sim, founder of non-profit group Base of Pyramid Hub, partnered with Dutch nutritional products manufacturer Royal DSM to blend nutritionally-fortified rice kernels with ordinary milled rice, and then sell it to caterers in Singapore.

The start-up, called 45Rice, provided over 200,000 meals for foreign workers last year and launched a mobile app platform to connect caterers using fortified rice with construction firms.

45Rice General Manager Kevin Moon told CNBC the company is hoping to get its products on the shelves of local supermarkets by the third-quarter of 2017, and it has plans to eventually expand into developing markets.

“Infusing our everyday foods with nutritional fortification will become especially important in the near future, especially as climate change begins to make a deeper impact on the availability and production of staple foods,” Pieter Nuboer, vice president of human nutrition and health at DSM, said in an e-mail to CNBC.

Nuboer also stressed the importance of innovation to help meet the demand of a growing global population and changing dietary choices.

Royal DSM has a project named “Proteins of the Future,” which extracts plant protein from the inedible by-products of rapeseed and canola oil extraction, he said. The plant proteins can then be added to sports nutrition or elderly nutrition products.

While government programs and fortified products can help food security, farms are ultimately the backbone of the industry.

But as supply chains consolidate, there has been a growing global warning that small-scale farmers need to be supported.

About 90 percent of the world’s farms are owned and operated by families, most of them are small and found in rural areas of the developing world, FAO data showed. Many of these smallholder family farmers are poor and food insecure, with limited access to markets and services.

Companies like Cargill need to support these smaller farmers, not by asking them to merge into a big firm, but by helping them increase productivity through service support and education of best practices, said Peter van Deursen, the Asia Pacific chief executive officer of Cargill.

“If you get production of smallholders up, you can raise their income and allow them to reinvest in the farm…these smallholders can be part of a solution (to food security) in some parts of the world,” he said.

Agritech — the buzzword for technology used to enhance farming systems and agricultural production — can also support small farms.

Anything from farm management software to precision agriculture and predictive analytics can be agritech, and some see it as a good investment.

“Agriculture is a risky business, as it is regulated by governments in most countries, and venture capital firms lack the domain expertise so very few invest in this sector,” said Arun Kant, chief executive and chief investment officer at Singapore-based investing firm Leonie Hill Capital.

But Kant told CNBC that as technology plays a bigger role in agriculture and as governments start to relax private investment regulations investors could see better returns from their investments. One of the firm’s latest investments, according to Kant, is in a start-up that supports small-scale dairy farmers in India by providing smart milk collection and other services.

Sanjay Nath, who told CNBC he was the founder of the company, said he saw an opportunity in the dairy industry because there was a need to reform the current unhygienic practices of milk collection, improve the safety and quality of the product and help farmers receive fairer incomes.

Euromonitor analyst Dilip Radhakrishna told CNBC the Indian dairy industry “is unorganized and cold storage facilities have not been well-developed.”

Indian dairy farmers are also disadvantaged by the “low procurement prices offered by the government and private bodies” and the “dominance of middle men at milk collection centers,” the analyst said.

“Food security, free trade and sustainability are a triangle of factors that are correlated with each other — one can’t be excluded from the other,” Cargill’s Van Deursen told CNBC.

The world’s current food production is actually sufficient to feed its 7 billion people, Van Deursen said, but protectionism is a major problem affecting the availability and affordability of food. The barriers to open trade prevent goods from moving freely from one place of surplus to another facing shortage.

The commodity giant chief cited Russia’s grain export ban in 2010 as an example of how one country’s protectionism leads to a major disruption to international food supply.

Grain prices rose as a result of the ban. Egypt, Russia’s biggest wheat customer, had to scramble to find alternative sources, and the government committed to subsidize grain and bread prices so as to avoid any public unrest. Pakistan, which was another big importer of Russian wheat, saw wheat prices surge just as the government was reducing food price protections and its poverty rate rose by 1.6 percent over a short period, according to a 2011 Oxfam report.

Sustainability is also another concern, as mounting pressure on natural resources and climate change impact agriculture and food production.

The negative effects of climate change also mean there needs to be a transformation of food and agriculture systems to protect the ecosystem upon which agriculture depends, according to a United Nation’s Food and Agriculture Organization (FAO) 2016 report.

The FAO report warned that climate change will hurt the productivity of crops, livestock, fisheries and forestry across all regions after 2030.