Snack attack - The bad dietary habits that are taking hold in Asia and Africa

A sweet, butter-filled bread roll, wrapped in plastic, has become the snack rickshaw rider Jewel Ahmed reaches for when he needs to eat while in traffic in Bangladesh's capital, Dhaka.

- Kaamil Ahmed

Bun roti, as the rolls are known, are sold for 10 Bangladesh taka (7p) at the same stalls where the city's rickshaw riders buy heavily sweetened tea to ward off hunger and tiredness.

"I often eat two or three of these a day with some tea. I still feel hungry sometimes, but these usually keep me going for a few hours," said Ahmed, 27, opening a packet and taking a large bite.

Bangladesh is not the only developing country where snacks are ever more prominent in diets, helping fuel busy workers through the day or children on journeys to and from school, and sometimes even replacing meals. For experts, the rise of unhealthy snack foods is concerning because of potential impacts on long-term health, such as diabetes and heart conditions.

Ahmed used to eat a more nutritious diet of fish and vegetables, but salinity in the rivers around his coastal home town of Bhola ended his livelihood in fishing and forced him into the city.

"Food in Dhaka is expensive and, with the cost of living crisis, even basic items are now unaffordable," said Ahmed, who chooses the bun roti over traditional, more substantial snacks such as vegetable-filled shingara pastries.