Which is best - the organic antipodean apple, the fair-trade banana or the pesticide-sprayed Home Counties plum?
Not every town has the use of a farmers' market
It is not easy being green when faced with hard choices at the fruit counter.
A report in the journal Food Policy has said locally-produced food is usually more "green" than organic.
Organic farming is valuable, it said, but people could help the environment more by buying food produced nearby - within a 20km radius of home.
So what is the best choice for the consumer with good intentions but no Good Life? Go local, go organic or go and forget about it?
"We would be looking for people to buy organic and local," says a doubly-demanding Vicki Hird, from Friends of the Earth.
When push comes to trolley-shove, it can feel like a struggle, but she believes people should demand better choices from supermarkets, shops and suppliers.
Faced with a trilemma between organic, local or fairtrade, but not all three, she said: "I would probably go for the local but make sure I washed it.
"But I probably wouldn't choose any of them - I would demand another option, go to another store.
"If people demanded more organic produce, we wouldn't have to make these choices.
"We recognise it's tricky for people in urban areas, but there might be more options than they think."
She recommends looking online and in the press for local food cooperatives, farmers markets and organic box schemes to find food straight from the producer.
And, she believes, people should go for fresh produce, free from pesticides: "Go for a lettuce and break it up yourself - if you find a slug, say, 'yes, I've got a slug - not yuck'," she says.
What is on the fruit, where is it from, what price did they get?
Direct sales of organic fruit, veg and other foods have boomed in recent years in the wake of food scares and obesity scandals.
The government promotes healthy eating; awareness about nutrition and the environment has grown - and even celebrity chefs are trying to turn children's hearts and minds to good nutrition.
Figures from organic champions the Soil Association show schemes delivering organic boxes rose from 306 to 471 in 2001/2. In 2002/3 total sales were up 19% from £35m to £41.6m.
Sales at farmers' markets - where producers sell directly to the customer - were up from £4m in 2000/1, to £8m the following year. In 2003/4, the number of farmers' markets increased from 450 to 500.
The argument over the benefits of eating organic continues. On current evidence the Food Standards Agency says organic food is not significantly different in terms of food safety and nutrition from that produced conventionally.
But the Soil Association says research shows there are more nutrients in organically-produced food.
It too says more research is needed. But its Organic Farming, Food Quality and Human Health report examined 400 research papers and showed evidence indicating organic food was safer and better on average.
Like FoE, the association plumps for ideal-world local and organic but also says in some cases imported organic products are better for the environment.
Organic box schemes have grown in number and profit
It depends on what food it is, the farming techniques and the transport used - for example sea versus air-freighted veg.
The researcher behind the food miles study, Professor Jules Pretty of the University of Essex says food miles - both in and outside the UK - are much more important in terms of environmental impact than thought.
People need to think harder about the cost of transport when picking out food.
"Local food is more important than green food," he says. "Although both will be best."
At the coal face of food shopping, Britain's biggest supermarket, Tesco stocks 7,000 regional lines from local producers.
"We aim to source locally where possible as and when the season allows," a spokesman said.
It says it listens to what customers want, and tries to meet that demand. It is an approach which has seen Tesco take about £1 in every £8 spent in Britain's shops.
And perhaps it is food for thought for any demanding shopper, wanting to go green.