Plant vs animal protein 'Low carbohydrate dietary patterns favouring animal-derived protein and fat sources, from sources such as lamb, beef, pork, and chicken, were associated with higher mortality,' the study said. 'Those that favoured plant-derived protein and fat intake, from sources such as vegetables, nuts, peanut butter, and whole-grain breads, were associated with lower mortality,' it said, adding that this suggested 'the source of food notably modifies the association between carbohydrate intake and mortality.' Seidelmann and colleagues poured over the medical histories of nearly 15,500 men and women who were 45-64 when they enrolled - between 1987 and 1989 - in a health survey spread across four locations in the United States. Participants filled out detailed questionnaires about their dietary habits - what foods, how much, how often, etc. Over a 25-year follow up period, more than 6,000 of the men and women died. People who got 50-55 % of their calories from carbohydrates outlived those with very low-carb diets, on average, by four years, and those with high-carb diets by one year. A review of medical records for an additional 432,000 people from earlier studies confirmed the results, which are also in line with World Health Organization (WHO) recommendations. 'There is nothing to be gained from long-term adherence to low-carbohydrate diets rich in fats and proteins from animal origins,' said Ian Johnson, a nutrition researcher at Quadram Institute Bioscience in Norwich, England, commenting on the research, in which he did not take part. But carb quality, not just quantity, is crucial he added. 'Most should come from plant foods rich in dietary fibre and intact grains, rather than from sugary beverages or manufactured foods high in added sugar.' Fibres also help maintain a healthy gut flora, now considered to be a major factor in health and disease. Plant vs