Replacing low-quality carbohydrate food in favour of high-quality food items could support efforts to control weight gain, a new study has found.
An example would be limiting the intake of items like added sugars and potatoes in the diet and replacing them with food items such as whole grains and fruits.
A prospective cohort study published in BMJ — a peer-reviewed medical journal published by the British Medical Association — finds a linkage between changes in carbohydrate intake and long-term weight changes.
It also found that among men and women, increases in glycemic index and glycemic load were positively associated with weight gain. It showed that with the concurrent four-year change in body weight, maximum weight gain was noticed with the intake of carbohydrates from starchy vegetables, mostly potatoes.
The study, where the mean age of participants was around 50 years, concludes that people who are trying to control their body weight should replace low-quality carbohydrate food with high-quality carbohydrate-rich food.
For instance: Added sugar, sugar-sweetened beverages, refined grains and starchy vegetables (potatoes, corn and peas) fall under low-quality carbohydrates whereas whole grains (millet, brown rice, and quinoa), fruits and non-starchy vegetables fall under good-quality carbohydrates.
The study titled “Association between changes in carbohydrate intake and long term weight changes: a prospective cohort study” observed the weight change within a four-year period.
“The findings of this study highlight the potential importance of carbohydrate quality and source for long-term weight management, especially for people with excessive body weight,” it said.
“Limiting added sugar, sugar-sweetened beverages, refined grains, and starchy vegetables in favour of whole grains, fruit, and non-starchy vegetables may support efforts to control weight.”
How was the study performed & what did it find?
The study was conducted on 1,36, 432 men and women less than or equal to 65 years who did not have any co-morbidity such as diabetes, cancer, cardiovascular disease, respiratory disease, neurodegenerative disorders, gastric conditions and chronic kidney disease.
The prospective cohort study, which includes follow-up from participants for 24 to 28 years, found that on average, participants gained 1.5 kg every four years, amounting to 8.8 kg on average over 24 years.
The study also found that among men and women, increases in glycaemic index and glycaemic load were positively associated with weight gain. However, more than 80 per cent participants in the study were women.
“For example, a 100 gram per day increase in starch or added sugar was associated with 1.5 kg and 0.9 kg greater weight gain over four years, respectively, whereas a 10 gram per day increase in fibre was associated with 0.8 kg less weight gain.”
It found that “increased carbohydrate intake from whole grains, fruit, and non-starchy vegetables was inversely associated with weight gain, whereas increased intake from refined grains and starchy vegetables was positively associated with weight gain”.
In substitution analyses, replacing refined grains, starchy vegetables, and sugar-sweetened beverages with equal servings of whole grains, fruit, and non-starchy vegetables was associated with less weight gain, it said.
“The magnitude of these associations was stronger among participants with overweight or obesity compared with those with normal weight. Most of these associations were also stronger among women.”
Dr Rajeev Jayadevan, Convener, Scientific committee and past President, IMA Cochin, said: “The study reinforces the dietary advice given out by nutritionists and doctors in that, reducing the intake of refined carbohydrates and sugars is helpful to maintain a healthy weight.”
He added: “From India’s perspective, there is a disproportionate amount of carbohydrates in the diet. And with socio-economic progress, more refined foods are finding place in our diets. One must also not forget the cost associated with following such diets.”
In particular, he emphasised that costly vegetables and fruits are not necessarily healthier than what is locally available. “For instance, banana and guava are cheap and easily available, while exotic fruits are more expensive.”
Anoop Misra, Chairman at Fortis-C-DOC Centre of Excellence for Diabetes, said: “High carbohydrate and low fibre contents of Indian diets are persistent problems, and harbinger of diabetes and heart disease. Changes to complex carbs, and increasing fibre in diet will benefit metabolic status of Indians, in line with this study.”
