John Lewis posted a jump in sales last week as warm weather and the continued healthy living trend boosted performance across categories.

The department store chain’s sales increased 4% to £73.1m in the week ending May 14, as sunnier weather influenced shoppers’ purchases in home and fashion.

John Lewis reported a 2.9% uplift in its home division as outdoor living products drove sales in the category. Low-tog duvets were highlighted as another “star performer” in the sector as most of the UK enjoyed sunnier spells.

The retailer said fashion sales grew 2.2% during the seven-day period, despite being up against a tough comparable week in 2015, which featured price-matching activity against promotions from competitors.

Childrenswear performed “particularly strongly”, John Lewis said, with sales up 29% on the year.

But electricals and home technology emerged as the strongest category during the week, enjoying sales growth of 8%. That was buoyed by a boom in purchases of wearable technology, which rocketed 352% compared to the same week last year.

John Lewis retail operations development director Simon Russell said it demonstrated that “customers are increasingly looking for products that will aid their healthy lifestyles”.

However, shoppers at sister retailer Waitrose seemed keen to forget about the calories and treat themselves to barbecues in the sunshine.

The upmarket grocer recorded a 4% increase in sales to £127.74m last week, driven by sales of barbecue meat and service-counter fish, which jumped 17% and 16% respectively. Barbecue fuel sales surged 95% during the seven-day period.

Shoppers also splashed out on alcohol, with sales of Pimm’s spiking 72% and beer climbing 20% year on year.

Al fresco dining was the order of the day for Waitrose customers, with picnic foods also enjoying “significant” growth.

Salad sales increased 12%, while soft fruit and food-to-go lines posted uplifts of 11% and 8% respectively last week.

Waitrose added that online sales grew by more than 10% compared to the same week last year.