Are long-term FAD diets restricting micronutrient intake? A randomized controlled trial

Area of Science:

• Nutrition Science
• Dietary Interventions
• Public Health

Background:

• Fad diets are popular but their micronutrient adequacy is often unexamined.
• Assessing the nutritional impact of common dietary patterns is crucial for public health.
• Obesity and diabetes are prevalent conditions often managed with dietary changes.

Purpose of the Study:

• To compare the effects of a high-fiber (HF) diet versus a low-carbohydrate (LC) diet on body weight and micronutrient adequacy.
• To evaluate the long-term (52-week) impact of these popular diets.
• To identify specific micronutrient shortfalls associated with each dietary approach.

Main Methods:

• Randomized controlled trial involving 173 adults (BMI 36 kg/m²), with or without diabetes.
• Participants were assigned to either a HF or LC diet for 52 weeks.
• Assessment included anthropometrics, blood lipids, glucose, blood pressure, and detailed micronutrient consumption analysis.

Main Results:

• The LC diet group demonstrated better weight loss retention compared to the HF group (p=0.06).
• LC dieters had higher intakes of vitamin K and vitamin B12.
• HF dieters consumed more folate, magnesium, and iron. Both groups had inadequate intake of vitamins D and E, and potassium.

Conclusions:

• While a LC diet may offer advantages for long-term weight management, it is associated with specific micronutrient intakes.
• The HF diet provides higher intakes of certain micronutrients but may be less effective for sustained weight loss.
• Both HF and LC diets, as implemented in this study, resulted in significant micronutrient deficiencies, underscoring the need for careful nutritional planning.