Researchers compared general nutrition advice to personalized nutrition advice in addition to an app that encouraged users to follow a diet. Older, overweight, and obese people benefited more from the personalized approach [1].
One size does not fit all
Appropriate diets can help people stay healthy even in old age. However, nutritional recommendations are designed for the average person and do not take into account the high variability in people’s nutritional needs and preferences. Personalized nutrition approaches address this need to optimize the diet for the individual. Such personalized nutrition can also be considered a therapeutic approach to preventing or managing chronic diseases.
However, sticking to a strict, personalized diet can be difficult for most people. The authors of the current study believe that digital tools can support and motivate individuals to adhere to a recommended diet. Therefore, they created a trial to determine whether personalized dietary interventions combined with a digital tool could impact the health of overweight and obese older adults.
Usual care or personalized diet?
The study included 127 participants aged 50 to 80 with a BMI of at least 27. Participants had to have at least one risk factor, such as type 2 diabetes, hypertension, high cholesterol, or sedentary behavior. The trial lasted 12 weeks, with a 3-month follow-up.
The normal care group followed the Healthy Eating Plate (Harvard) and the dietary guidelines of the Spanish Association for Community Nutrition. These guidelines include recommendations on food groups, portion sizes, frequency of consumption, and practical tips for designing menus.
They also attended online sessions to learn about prescribed dietary patterns, food label use, seasonal shopping lists, meal plans and recipes, and sleep habits.
The sensitive diet group was given guidelines to follow a Mediterranean and mixed diet that included foods based on personal preferences, such as smoothies, fruit compotes, and whole wheat bread. These foods were specifically designed for this study and their ingredients were selected to prevent age-related diseases. Additionally, only members of this group were assessed for their calorie intake needs and attended visits to monitor compliance with the diet.
The sensitive diet group’s app was also specifically designed for this study with the needs of older adults in mind, was easily accessible and easy to use. It included information about the assigned diet, reminders about follow-up visits, and motivational messages.
At the end of the study, participants completed a dietary intake questionnaire reminding them of their 7-day food consumption, physical activity, and health status, and took tests to assess cognitive functions.
Nutrition on the way to better metabolic parameters
Analysis of the data revealed that after three months of the diet, both groups experienced significant reductions in body weight, BMI, and diastolic blood pressure. However, changes in the sensitive diet group were significantly greater than those in the usual care group.
There were also differences between groups. On average, participants following the precision diet intervention finished the study with lower waist circumference, waist-to-hip ratio, fat mass, and systolic blood pressure compared to the usual care group.
The researchers also measured biochemical parameters, and both groups showed significantly better triglyceride and uric acid concentrations, which were not significantly different between groups. Uric acid was used here as a marker of the anti-inflammatory effects of the dietary strategies, suggesting that both dietary approaches affect the inflammatory aging environment (inflammaging). However, more inflammatory biomarkers need to be evaluated to better understand the underlying mechanisms behind these diets.
The sensitive diet group also had significantly lower total cholesterol and HDL-c levels, and improved glycemic control and markers of liver health, compared with both the baseline and usual care groups.
The researchers measured total energy intake but observed no difference between the groups. However, the groups differed in certain nutrient groups; carbohydrates, proteins, and fiber content were significantly higher in the sensitive group, and lipids were lower.
The sensitive group also consumed less sodium but more sugar than the usual care group. The researchers note that most of the sugars in the participants’ diets came from fruits, vegetables, and dairy products. While free sugars should be limited in the diet, there is no evidence of adverse effects from consuming sugars naturally found in fruits, vegetables, or dairy. The results of this study support this, as the researchers did not observe any adverse effects on glucose metabolism in the sensitive group participants. They hypothesize that fiber and “interactions with other nutrients may positively affect the regulation of glucose homeostasis and metabolism.” [2].
Better nutrition, better quality of life
Based on questionnaires completed by participants after completion of a 3-month study, members of the precision diet group reported improved quality of life. Specifically, the precision diet group reported improvements in the vitality, body pain, and emotional role portions of the quality of life test. Both groups reported improvements in general health and physical function. Statistical analysis revealed several associations between the metabolic changes observed in participants and improvements in well-being.
The authors believe that in the future, the use of big data and -omics technologies will enable even more personalized nutritional approaches. Such a strategy has the potential to better help develop nutritional approaches that can help avoid diseases and reduce the effects of aging.
The researchers point out several limitations of the study, including not assessing baseline dietary intake, potential biases from self-reporting, low sample size, not assessing the mobile app alone (only in combination with diet), and the impossibility of conducting a double-blind trial due to the nature of the intervention.
Literature
[1] Galarregui, C., Navas-Carretero, S., Zulet, MA, González-Navarro, CJ, Martínez, JA, de Cuevillas, B., … & Abete, I. (2024). Impact of precision nutrition on metabolic health and quality of life in an aging population after a 3-month intervention: A randomized intervention. Journal of nutrition, health and aging, 28(7), 100289.
[2] Müller, M., Canfora, EE and Blaak, EE (2018). Gastrointestinal transit time, glucose homeostasis and metabolic health: modulation by dietary fibres. Nutrients, 10(3), 275.