Switching to a healthy diet, rather than maintaining an unhealthy diet, could potentially add nearly nine years to life expectancy.
In the United Kingdom, fewer than 0.1% of adults consistently follow the guidelines for a healthy, balanced diet as outlined by the U.K. Government’s Eatwell Guide. A study from the U.K. Biobank has demonstrated that adopting the diet prescribed by the Eatwell Guide, rather than maintaining an unhealthy diet, could potentially add nearly nine years to life expectancy. For those already following the “median” diet, which only partially aligns with the Eatwell Guide, transitioning fully to the recommended diet could result in a life expectancy increase of about three years.
The study’s authors emphasize the importance of sustained efforts to facilitate healthier dietary habits across the adult population, aiming to reduce the health impact of dietary-related diseases.
According to the World Health Organization (WHO), poor diet and physical inactivity are recognized as “leading global risks to health.” To address these issues, WHO collaborates with countries on initiatives to eliminate trans fats, reduce salt intake, and establish guidelines for food labeling and the use of artificial sweeteners.
In the United Kingdom, the Government introduced the Eatwell Guide in 2016 to support adherence to a healthy, balanced diet. This guide highlights the importance of consuming at least five portions of fruits and vegetables daily, reducing salt and saturated fat intake, and encouraging whole grains and pulses, with recommendations on portion size and calorie intake.
Despite these efforts, research published in BMJ Open reveals that fewer than 0.1% of the U.K. population currently follows a diet in full accordance with the Eatwell Guide’s recommendations.
The Influence of Healthy Diets on Longevity
Since 2006, the U.K. Biobank has tracked the health of 500,000 U.K. residents aged 40 to 69, gathering comprehensive data on dietary habits and overall health. Recently, researchers from the University of Bergen, Norway, analyzed dietary data from over 465,000 of these participants to examine the impact of adherence to the U.K. Government’s Eatwell Guide on life expectancy. The study’s findings were published in Nature Food.
Participants’ dietary patterns were evaluated, with food intake across groups divided into quintiles from lowest to highest. Quintiles associated with lower mortality risk were identified as those that most closely aligned with longevity-focused dietary patterns.
Unhealthy dietary habits were marked by low intake of whole grains, vegetables, fruits, fish, and white meat, but higher consumption of red and processed meats, eggs, refined grains, and sugary drinks. Findings were reported based on participants’ alignment with the Eatwell Guide’s recommendations.
Data were adjusted to account for factors such as age, sociodemographic conditions, smoking, alcohol consumption, physical activity, and body mass index (BMI).
Results indicated that a 40-year-old man transitioning from an unhealthy diet to one following Eatwell Guide recommendations could potentially extend his life expectancy by 8.9 years, while a woman of the same age could see an 8.6-year increase. For a 70-year-old man, this shift was linked to a four-year increase in life expectancy, and a 4.4-year increase for a woman of the same age.
When further adjusted for BMI and total energy intake, the predicted gains in life expectancy attributable to dietary improvements showed a slight reduction.
Meat Consumption and Increased Mortality Risk
Lead researcher from the University of Bergen, and head of a research group at Haukeland University Hospital noted:
“Our analyses and other research indicate that what is eaten is linked to the risk of obesity, a significant contributing factor to premature deaths. Our findings suggest that the risk of premature death related to overweight or obesity could account for about a quarter of the dietary risk increase from unhealthy eating.”
Prof. Lars Fadnes
The study also identified foods with the most substantial effects on reducing mortality risk. Increased consumption of whole grains and nuts, alongside reduced intake of red meat and sugary drinks, was associated with the most significant gains in life expectancy.
Socioeconomic Factors Influence Diet Quality
The study authors noted that with so few individuals adhering strictly to a healthy diet, the data for this group provided lower certainty.
“In our analyses, comparisons were not limited to groups fully following every guideline but included all population segments following recommendations to varying degrees, allowing a view of the cumulative health benefits contributed by each guideline.”
Prof. Lars Fadnes
Some food group categories were less evenly distributed across quintiles of intake, leading to fewer participants in certain categories and resulting in reduced precision and greater uncertainty for those groups.
The authors recommended sustained, multi-sector efforts to improve dietary habits across the U.K., such as implementing taxes on unhealthy foods and lowering costs for healthier options.
Dr. Linia Patel, a dietician and spokesperson for the British Dietetic Association, emphasized that socioeconomic factors play a significant role in an individual’s ability to maintain a healthy diet. Drawing from her research on the DASH diet, which aims to lower blood pressure and reduce cardiovascular risk.
“There is solid evidence supporting the Eatwell Guide as a foundation for a healthy diet. The benefits of consuming more whole grains, legumes, and plant-based foods are well-established. This study adds value by quantifying these benefits in terms of life expectancy.”
Dr. Linia Patel
Critiques of the Eatwell Guide and Population Representation
Dr. Patel highlighted that the Eatwell Guide has faced criticism for its lack of inclusivity regarding South Asian diets and those commonly followed by Black individuals in the U.K. Additionally, caution was expressed regarding the representativeness of the U.K. Biobank cohort in reflecting the entire population.
“[If] U.K. Biobank data is examined—despite the fact that a study is currently being conducted on it—it is not very representative. […] It presents a narrative, but not necessarily the most accurate one, as the population group is predominantly Caucasian and not from low socioeconomic backgrounds. Thus, it provides part of the story, but not the complete picture.”
Dr. Linia Patel
While such data are valuable, Dr. Patel noted that they do not fully indicate the best strategies for shaping policies aimed at improving dietary habits.
Given the low adherence rates to the Eatwell Guide, she emphasized the need for policies that ensure the diet is accessible and achievable for the broader population. Alongside the policy suggestions put forth by the authors and others, the importance of education in promoting healthy nutrition was underscored.
“Beans and lentils are known to be relatively inexpensive, yet there is still a lack of usage. Why is this the case? What barriers exist? Questions like these must be explored to effectively translate research findings into practical policy applications.”
Dr. Linia Patel
https://doi.org/10.1038/s43016-023-00868-w
Abstract
Adherence to healthy dietary patterns can prevent the development of non-communicable diseases and affect life expectancy. Here, using a prospective population-based cohort data from the UK Biobank, we show that sustained dietary change from unhealthy dietary patterns to the Eatwell Guide dietary recommendations is associated with 8.9 and 8.6 years gain in life expectancy for 40-year-old males and females, respectively. In the same population, sustained dietary change from unhealthy to longevity-associated dietary patterns is associated with 10.8 and 10.4 years gain in life expectancy in males and females, respectively. The largest gains are obtained from consuming more whole grains, nuts and fruits and less sugar-sweetened beverages and processed meats. Understanding the contribution of sustained dietary changes to life expectancy can provide guidance for the development of health policies.