The UK topped the charts, followed by the US and Australia.
Published in the journal Obesity Reviews, the researchers analysed more than 400,000 food and drink products from 12 countries and territories around the world.
The survey highlights the high levels of sugar, saturated fat, salt and calories/kJ in several of our favourite food items.
The countries were ranked using Australia's Health Star Rating system which measures the levels of the nutrients such as energy, salt, sugar, saturated fat as well as protein, calcium and fibre and assigns a star rating from half least healthy to five the most healthy.
It was found that the UK had the highest average Health Star Rating of 2.83, followed by the US at 2.82 and Australia at 2.81.
Among the lowest were India with just 2.27 rating, China with 2.43 and Chile 2.44.
The research also found that China's drinks were among the healthiest with an average Health Star Rating of 2.9 but packaged foods scored low at just 2.39.
South Africa on the other hand scored low with its drinks at an average 1.92 rating while its foods came in at 2.87.
The UK scored best for sugar at just 3.8 grams per 100 grams, with Canada being the second best at 4.6 grams per 100 grams.
The results were concerning because packaged foods and drinks are driving a double burden of diet-related diseases in many low- and middle-income countries, researchers said.
"Our results show that some countries are doing a much better job than others. Unfortunately, it's the poorer nations that are least able to address the adverse health consequences that have the unhealthiest foods," said study lead author Elizabeth Dunford from the George Institute for Global Health.
"Billions of people are now exposed to very unhealthy foods on a daily basis. The obesity crisis is just the first ripple of a tsunami of dietary ill health that is coming for us," she added.
( With inputs from IANS )