"We are overdosing on macronutrients, especially meat, dairy, alcohol and sugar, so we need to dial these down if we want to be healthier," Mayell said.
"And we need more micronutrients, so we need to dial up whole plant foods, especially leafy greens. Plant food is simply better for your body."
A study published in February by Imperial College London showed a healthy diet should include 10 portions of fruit and vegetables a day, but according to Mayell, 60 per cent of New Zealanders didn't eat the Ministry of Health's recommended five plus servings a day.
"We know we should be eating more fruit and veges but for many of us life gets in the way," Mayell said.
"For parents trying to get more greens into the family diet or young people juggling work, study and play, it's not easy to get that recommended intake."
Nutrient Rescue sells a Green Shot of wheat grass, barley grass and other greens; a Red shot - powdered blackcurrants and boysenberries - and a double shot, which combines the two sachets.
Mayell, who still owns half of Cookie Time, said sales had started strongly and he hoped to continue expanding the business.