Over the 10 years I have had children, feeding them has become an increasing burden. Everywhere I look I find reasons to feel anxious and guilty. These days, for example, I tend to avoid the supermarket fish counter, in the hope that forgoing a few omega fatty acids will ensure there is still some cod around when my daughters are old enough to trawl the aisles. I make a beeline for the fruit and veg section, only to find myself agonising over how to fulfil my five-a-day obligation. Oppressed by the stonking great carbon footprint on all the imported fruit, I search in vain for the Great British "apple a day" that might keep the doctor away.

In my head I hear my mother's voice, just a little bit smug – "We never had those sorts of problem when you were growing up … " I know, I know. And everyone was healthier and slimmer; and they didn't throw anything away.

When my first child, Ellie, was born, Mum gave me a treasured heirloom – her mother's recipe book. Bound in linen, its spine a little torn and battered after more than six decades of hard labour, it was more than a piece of memorabilia. There, in Granny's careful, Edwardian hand, I was being offered access to a whole new way of life.

Leek flan, bacon and cheese pie, eggs florentine …

From the spattered pages arose all sorts of comforting associations – fresh spinach, dry and earthy on my sensitive young tongue; Granny bowed over her red formica table, rolling out pastry. Her cooking was a response to the limitations of government rations rather than the cornucopia of the supermarket; the dishes were wholesome and reassuring – perfect nursery food.

As my children got older, I found myself preferring this family cookbook to the celebrity-fronted alternatives on my shelves. I found it infinitely more practical and imaginative. It was particularly useful when we got an allotment and needed to remember what to do with a glut of courgettes or tomatoes that refused to ripen. Later, when I took Ellie pet-shopping and came home with a couple of chickens, it offered all that Granny could teach about home-reared eggs.

My grandparents were very happy keeping chickens in the back garden during the era of Dig for Victory. When the war ended and egg production was taken over by the corporations, Grandpa still kept herding his Rhode Island Reds around. I had vague memories of myself as a toddler, confronting those prehistoric creatures, and later the thrill of discovering their eggs – so much better for you than shop-bought ones, Grandpa said.

It has taken a while for science to catch up, but recent research from the US Department of Agriculture agrees – hens foraging on pasture produce eggs containing 34% less cholesterol than those on industrial feed. Industrial feed is what modern commercial chickens eat (whether caged or not, organic or not) – dusty grey pellets said to contain all they need for a healthy existence. Eggs from those non-industrial American hens are also 10% lower in fat, 40% higher in vitamin A, offer twice as much omega-6, and four times as much omega-3 … the sort of nutrition profile that any fish would be proud of.

For those of us suffering footprint guilt, industrial feed is a bad idea even before it affects the egg. This is because its main protein content is soya meal – most likely, Brazilian soya grown where there used to be glorious, carbon-capturing rainforest.

It didn't used to be like that, of course. Though Granny's recipe book only contained dishes for human consumption, I remember well enough what her pre-pellet hens used to eat: all the wild stuff they could forage – grass and bugs and worms; a scattering of corn from the local farm; loads of greens – old cabbages or weeds hung with a piece of string from the bars of their run; slugs and snails from the veg plot; and kitchen scraps.

The amount of scraps available in my kitchen would have appalled my grandparents – on top of the carrot peelings come my children's breakfast cereal swimming in milk, and far too much of that wholesome fare I had so earnestly provided. The idea of feeding leftovers to the chickens came as a huge relief. No more long-winded suppers, having to serve up a lecture on the starving millions. Instead, I began whisking away the children's plates with – "Great – the chickens will love that."

The retro chicken feeding regime inherited from my grandparents offers all sorts of novel forms of entertainment. A drizzly day becomes an opportunity for a snail hunt. Little Bea always manages to find a good dozen gastropods beneath any pot or stone. I even manage to persuade her that it's fun helping me to pull dandelions and other delicacies from the pavements or from the borders of her playground.

Both daughters appreciate the results in the kitchen: the way breakfast sits up pertly in the frying pan, rather than flat and omelette-like; the way the yolks change colour depending on what the hens ate the day before. A supper of cow parsley or cabbage leads to something much more interesting – a glorious, sunshine yellow sometimes tending to emerald.

Having established that 21st-century chickens thrive on a 1940s diet, I recently expanded my flock. There are now six birds in our modest back garden, just as there might have been half a century ago. The five minutes a day I invest in feeding and watering them is well worth it, when the returns are so satisfying: cheap, delicious, healthy eggs in abundance. And a serious reduction in anxiety and guilt.

Which means that I at last feel able to open up the extensive puddings section in Granny's recipe book. Raspberry soufflé, fancy rhubarb pie, baked apple pudding … My girls won't be leaving any of these on the plate. I wonder if a double portion of the soufflé might qualify as half their five-a-day count?

Julia Hollander's book Chicken Coops for the Soul is published by Guardian Books at £12.99. To order a copy for £8.99 with free UK p&p, visit guardianbooks.co.uk or call 0330 333 6846