A healthy, nutritious diet is one of the most basic human needs. But billions of people don't; they suffer from "hidden hunger" and micronutrient deficiencies, such as too little iron, calcium, vitamin A or iodine.
There are many reasons why someone might not eat a nutritious diet. Usually because people can't afford it.
Studying local food price data from the International Comparison Program (ICP) answers the lowest-cost options for meeting basic nutritional needs. and matched with other data on food composition and dietary requirements.
Hundreds of millions of people cannot afford an energy-sufficient diet
Let's start with the most basic requirement: getting enough calories. These calories can come in any form, but in most countries the cheapest options are starchy foods and cereals. Adopting this "energy-rich" diet means eating only cornmeal or rice at every meal, which is severely lacking in all other important nutrients. When you look at what people eat, you'll find that in poor countries, people get most of their calories from starchy foods.
A person can eat an energy-sufficient diet for less than $1 a day. The global average price of this diet across all countries included in the study was US$0.83 per day.
People with higher incomes spend much less on food. The relationship between our income and food expenditures follows a fairly consistent pattern, with the proportion we spend on food decreasing as our income increases (even as the total amount we spend on food increases).
This means that the poorest households spend a large proportion of their income on food. The 52% threshold is the proportion that the lowest income group typically spends on food .
By comparing diet costs and income distribution around the world, researchers estimate that 381 million people cannot afford a basic energy diet.
Today, we might think of this calorie adequacy threshold as equivalent to the nutritional international poverty line of $1.90. This is the absolute minimum.
Three billion people cannot afford healthy meals
What people really need is a varied, nutritious diet. Getting enough calories is important, but it's not enough to live a healthy and productive life. Eating only grains and starches can leave you deficient in protein, essential fats, and various micronutrients your body needs to function optimally.
Most countries have developed "food-based dietary guidelines" that provide recommendations for "healthy eating." These include guidance on what balance of a variety of foods, including grains, fruits, vegetables, legumes, meats and dairy products, is considered best for long-term health.
A varied, healthy diet is much more expensive than a calorie-sufficient diet. The average cost worldwide is $3.54 per day. When we put these prices into the context of affordability, we find that 3 billion people cannot afford to eat healthy. In many of the world's poorest countries, especially in sub-Saharan Africa, it's out of reach for most people. In many countries, more than 90% of people do not have access to a healthy diet.
How do incomes around the world compare with the price of healthy eating?
A useful way to understand the context of food prices is to compare the cost of a healthy diet with the median income of countries around the world.
In the poorest countries, the cost of a healthy diet is higher than the median income. Even if the average person in these countries spends all their money on food, eating healthy is unaffordable.
In some countries (the largest of which is India), the cost of eating will be roughly equal to the median income. People there need to spend all their income on food to afford a healthy diet.
The richest country in the world. There, the median income is much higher than the cost of food and drink. In these countries, middle-income earners can afford a healthy diet at a fraction of their income. The average French person only spends 6% of their income on food. In Denmark, it's only 5%.
This comparison shows just how far away most of the world is from being able to afford a healthy diet. We cannot spend all or even most of our income on food. We have little money left to spend on other necessities such as energy, housing, clothing, education, and health care.
The world has come a long way in making a calorically adequate diet more attainable. Malnutrition is no longer the default condition it once was. The world has succeeded in achieving this through advances in agricultural technology: we can now grow more food. At the same time, global revenue grew significantly.
The ratio of food prices to income is key. If we are to make healthy eating affordable for everyone, we need to see a significant increase in real incomes. An increase in real income means economic growth.
