Discussion
weight loss
The aim of the study was to determine the effects of multi-level supermarket discounts on fruits, vegetables, and non-caloric beverages on their dietary intake and on clinical markers of health. In this interim data analysis, we examined changes from the end of the baseline period to the midpoint of the intervention period. The results showed that the discounts led to significantly increased consumption of both vegetables and diet soda in the 30% discount group. The 15% discount group showed a non-significant increase in consumption of diet soda but no change for vegetables. Thus, a discount of 15% may not be adequate to influence vegetable intake. Unlike vegetable intake which increased following the 30% discount, there was no effect of the discounts on fruit intake.Americans do not follow the dietary guidelines for fruits, i.e., adults ages 19–59 scored 2.4 out of 5 on total fruit consumption according to the 2017–2018 Healthy Eating Index [Although the discounts led to an increase in diet soda consumption, there was no effect on the intake of discounted bottled water and seltzer water. It is possible that in their dietary recall, participants failed to consistently distinguish bottled water from tap water. Also, seltzer water is consumed much less in comparison to diet soda, and may not have been sufficiently sensitive to the effects of the discounts.The 30% discount led to a significant increase in diet soda. At the same time, there was a non-significant decrease in regular soda intake during the intervention period in the 30% group as compared to the control group; however, the inverse correlation between diet soda intake and regular soda intake was highly significant, indicating a strong relationship. This significant correlation suggests the increase in diet soda intake led to a decrease in regular soda intake.There were no significant effects on body weight and body fat by the discount intervention. There was also no significant change in total daily caloric intake. A discount of 30%, or 15%, may not be adequate to produce a reduction in caloric intake or body weight. It may also take longer than 16 weeks for changes in body weight and fat to manifest following a 30% discount.There was a marginally significant effect of the COVID-19 pandemic to increase body weight. Similarly, Lin et al. showed a significant increase in body weight as a result of the COVID-19 pandemic [Our results are mostly consistent with other supermarket studies. Two studies [In the Australian study [In a supermarket RCT [Due to low intake of fruits and vegetables by SNAP participants, the USDA Food and Nutrition Service began the Healthy Incentives Pilot (HIP) to test a randomly assigned 30% incentive for fruits and vegetables in Springfield, Mass. The 30% incentive was added back to the person’s Electronic Benefit Transfer (EBT) card after purchases. Daily fruit and vegetable intake for HIP participants via 24-h dietary recall was about 25% higher after 4–6 months of the program than for the control SNAP group who did not receive the incentive [In the current study, we did not observe significant changes in body weight or other clinical measures. The changes in dietary intake that we observed may not be adequate to promote changes in clinical measures, such as blood pressure, lipids, and glucose, without some degree of weight loss [