The study sought to gain a better understanding of the role of potatoes and the glycaemic index in weight loss, largely because some have questioned the inclusion of potatoes in a weight loss regimen due to the vegetable's designation as a high glycaemic index (HGI) food.
"The results of this study confirm what health professionals and nutrition experts have said for years; when it comes to weight loss, it is not about eliminating a certain food or food groups, rather, it is reducing calories that count," said lead researcher Dr. Britt Burton-Freeman, PhD, MS. "There is no evidence that potatoes, when prepared in a healthful manner, contribute to weight gain. In fact, we are seeing that they can be part of a weight loss programme."
Researchers studied 86 overweight men and women over the course of 12 weeks to measure the effects of a reduced-calorie modified glycaemic index diet with the addition of potatoes. The subjects were randomly assigned to three groups and each had a diet that included five to seven servings of potatoes per week. The results indicated that all three groups lost weight.
One group was given a list of foods with a low glycaemic index (LGI) to include in their diet daily. The second group was given a list of foods with a HGI to include in their diet daily. Both groups were to reduce their daily caloric intake by 500 calories while also consuming five to seven servings of potatoes each week. All participants were guided and monitored for compliance by a dietitian to only eat foods on their lists or like foods along with the provided potatoes.
Participants in the third group - called the "control group" - were allowed to choose their daily meals and caloric intake on their own, but were encouraged to adhere to the U.S. dietary guidelines and the food guide pyramid. The only requirement of the third group was - like the other two groups - they had to include five to seven servings of potatoes each week.
All subjects were provided recipes and counselled accordingly for successful dietary adherence. The results indicated that all three groups lost weight and there was no significant difference in weight lost between the low and high glycaemic index groups.
This is good news for potato lovers and any consumer who craves the satisfaction of wholesome yet healthy meal options. One medium-size (5.3 ounce) skin-on potato contains just 110 calories per serving, boasts more potassium (620g) than a banana, provides almost half the daily value of vitamin C (45 per cent), and contains no fat, sodium or cholesterol.
"We're thrilled with the results of this study," says Kathleen Triou, vice president of domestic marketing for the United States Potato Board (USPB). "For the last few years the humble spud has been vilified in respect to its weight management properties. Now we realise that it should be glorified for its role in healthy weight loss."