Dietary Transitions and Health Outcomes in Four Populations - Systematic Review

Area of Science:

• Nutritional Science
• Epidemiology
• Public Health

Background:

• Non-communicable chronic diseases (NCDs) were historically rare in traditional, non-western populations.
• Industrialized diets and lifestyles have led to a rise in NCDs such as obesity, type 2 diabetes, heart disease, and cancer.

Approach:

• A systematic literature review was conducted to analyze the impact of dietary and lifestyle transitions on NCDs.
• Eleven populations undergoing nutrition transitions were assessed, with a focus on four diverse groups (Yemenite Jews, Tokelauans, Tanushimaru Japanese, Maasai) to explore diet-health outcome relationships.
• Data from seven additional populations were reviewed to mitigate potential bias.

Key Points:

• Populations replacing animal or plant-based saturated fats with refined carbohydrates experienced negative health outcomes, including increased obesity and diabetes.
• Increased sugar intake (600-650%) was strongly associated with NCDs in Yemenite Jews and Tokelauans.
• Maasai experienced increased BMI and diabetes with a transition to lower fat and higher carbohydrate intake.

Conclusions:

• Increased consumption of sugar and refined carbohydrates is strongly associated with negative health outcomes, particularly obesity and type 2 diabetes.
• While increased caloric intake and reduced activity contribute to NCDs, the primary dietary driver identified was increased refined carbohydrates.
• NCDs in these populations were not attributable to saturated fat or total fat consumption but rather to the replacement of fats with refined carbohydrates and sugars.