Eating a Moderate Amount of Carbs May be Best Health Option
Low-carb and high-protein diets have become increasingly popular, but a recent study suggests that moderate carbohydrate intake may actually be optimal.
Participants in the study included 15,428 between the ages of 45 and 64 people who took part in the Atherosclerosis Risk in Communities Study between 1987 and 1989. The men consumed between 600 and 4200 kcal per day, while the women consumed between 500 and 3600 kcal per day. People with extreme high and extreme low caloric intake were excluded from this analysis.
All the participants completed a dietary questionnaire at the beginning of the study and then again six years later. The questionnaire included questions about the types of food and beverages consumed, as well as portion size and how often people ate. The researchers used that data to determine the cumulative average of calories derived from carbohydrates, fats, and proteins. They then assessed the association between overall carbohydrate intake and all cause-mortality after adjusting for age, sex, race, total energy intake, education, exercise, income level, smoking, and diabetes. During a median follow-up of 25 years, 6,283 people died.
After analyzing the data, the researchers found that consuming less than 40% of calories from carbohydrates and more than 70% of calories from carbohydrates were both associated with a higher risk of mortality than consuming between 50% and 55% of calories from carbohydrates. They also found that from age 50, the average life expectancy of a person with moderate carbohydrate intake was 33 years, compared with 29 years for very low intake, and 32 years for high intake.
For the second part of the study, the same researchers performed a meta-analysis of eight prospective cohorts that included a total of 432,179 people in North America, Asia, and Europe. They found similar results, with both low and high carbohydrate intake associated with lower life expectancy, when compared with moderate intake.
Finally, they found that replacing carbohydrates with plant proteins and fats was associated with a lower risk of mortality than replacing them with proteins and fats from animals.
Researchers from Brigham and Women's Hospital led the study. It was published on September 1, 2018, in The Lancet.