A new study determined if adhering to the Nordic diet is associated with long-term changes in weight, waist circumference, and body mass index.
The Nordic diet, typically defined as a diet based around the traditional foods of the Nordic countries, supports the use of locally-sourced ingredients. This diet is rich in fish, grains, vegetables and berries. The Nordic diet is commended as an eco-friendly diet that emphasizes equally on nutrition and sustainability.
Both the Nordic diet and the Mediterranean diet have been shown to be effective for weight loss. However, the Nordic diet is different from the Mediterranean diet as the Nordic diet promotes the use of canola oil and rapeseed oil instead of olive oil. The Nordic diet also does not contain any processed foods or red meat and is based on home-cooked meals containing proteins, complex carbohydrates and healthy fats.
Obesity is a growing global epidemic
Overweight and obesity are rising health problems. There is ample evidence to suggest that weight gain is associated with an increased risk of coronary heart disease, type 2 diabetes, cancers, hypertension, and other health problems.
Over the past three decades, changes in diet have resulted in increased consumption of fat, meat, added sugars, and bigger portion sizes. Improved access to unhealthy food and decreased physical activity are primarily responsible for an increased prevalence of obesity and overweight.
With the current prevalence of obesity, there is a need for changing dietary patterns that support achievement or maintenance of healthy body weight.
Is the Nordic diet effective for weight loss?
There is a rising number of different types of diets that are effective for weight loss. Several studies suggest that the Nordic diet, which features foods sourced from or traditionally eaten in Denmark, Finland, Iceland, Norway, and Sweden, may help foster weight loss and lower body mass index (BMI).
Some studies show that adherence to the Nordic diet is associated with lower waist circumference, while some other studies have indicated improved heart health with the Nordic diet. However, scientists are still working to understand the effects of this diet on weight loss and weight maintenance.
A new study published in the British Journal of Nutrition examined the association between the healthy Nordic diet and long-term changes in measures such as weight, BMI, and waist circumference. The study focused on the adherence to Nordic diet not only at the start of the study but also sustained adherence throughout the seven-year-long follow-up. The researchers also aimed to examine the consistency between the self-reported and nurse-measured values of height, weight, and waist circumference.
The study included 5024 participants from Finland, aged between 25-75 years. One-third of the participants were evaluated by health examination and food frequency questionnaires. The rest of the participants were sent a measuring tape with instructions to measure height, weight, and waist circumference and a food frequency questionnaire.
The Baltic Sea Diet Score (BSDS), a tool for assessing healthy eating in Nordic countries, was used to determine the level of adherence of participants to the Nordic diet. The scores ranged from 0-25, with higher scores indicating a greater adherence to the healthy Nordic diet by the participants. Statistical analysis was used to evaluate the association between diet scores at the start of the study and during the follow-up period with the changes in weight, BMI, and waist circumference.
Adherence to the Nordic diet promoted long-term weight maintenance
The results showed that a lower Nordic diet adherence score at the start of the study was associated with a greater increase in weight, BMI, and waist circumference. In perspective, the participants who had a higher adherence to the Nordic diet were able to either lose weight or maintain their weight over the follow-up period.
The researchers also observed better weight maintenance or reduced weight and BMI of the participants who increased the adherence to Nordic diet during the follow-up period. The results showed no association between increased adherence to the Nordic diet and change in waist circumference.
Self-reported and nurse-measured values were consistent
The researchers observed high agreement between the height, weight, and BMI values measured by the nurse with those self-reported by the participants, thus implying that both the values used for analysis were reliable and did not need correction.
In addition to the strong agreement between the nurse-measured and self-reported values, other strengths of this study include a high participation rate of 82% and a sample of participants from the general population of Finland. The main limitation of the study, as stated by the authors, is the overestimation of values usually associated with food frequency questionnaires, which may have led to misclassifications.
Better adherence leads to better results
The researchers concluded that adherence to the Nordic diet is key in the long-term weight maintenance. In addition to a high adherence at the start of the study, an increased adherence during the 7-year follow up promoted long-term weight maintenance in this study. In line with past research, a Nordic diet that is rich in fruits, vegetables, whole grains, fish, and nuts, and no processed foods, prevent overweight and obesity. The authors suggest the need for future studies to confirm the benefits associated with the consumption of a healthy Nordic diet.
Written by Preeti Paul, MS Biochemistry
Reference: Noora Kanerva et al. Adherence to the healthy Nordic diet is associated with weight change during 7 years of follow-up. British Journal of Nutrition (2018), 120, 101-110. Doi:10.1017/S0007114518001344