Changes in diet quality during a 12 month weight loss randomised controlled trial

Area of Science:

• Nutritional Science
• Public Health
• Dietary Interventions

Background:

• Weight loss trials often show reduced energy intake, but improvements in diet quality (DQ) are less understood.
• This study evaluated changes in DQ within a weight loss intervention trial.

Purpose of the Study:

• To assess the impact of a lifestyle intervention on diet quality.
• To compare the effectiveness of individualized advice and walnut supplementation on DQ.

Main Methods:

• Secondary analysis of dietary data from the 12-month HealthTrack lifestyle intervention trial.
• Three groups: control (general advice), intervention (individualized advice), and intervention plus walnuts.
• Diet quality assessed using the a priori diet quality score (APDQS) and Diet Quality Tracker (DQT) at baseline, 3, and 12 months.

Main Results:

• The intervention plus walnuts (IW) group showed higher DQ scores at 3 months compared to intervention (I) and control (C) groups.
• All groups reduced discretionary food/beverage intake; IW and I groups showed significant reductions in salty snacks.
• The IW group had lower saturated and monounsaturated fatty acids, and higher polyunsaturated fatty acids, improving the P:S fat ratio.

Conclusions:

• Lifestyle interventions can significantly reduce discretionary food and saturated fat consumption.
• Individualized advice appears more impactful for improving overall DQ.
• Supplementation with healthy foods like walnuts can enhance DQ and favorably alter fatty acid profiles.