An Examination of Medically Necessary Diets within the Framework of the Thrifty Food Plan

ABSTRACT

The Thrifty Food Plan (TFP) determines the maximum allotment of nutrition assistance for over forty million Americans participating in the Supplemental Nutrition Assistance Program (SNAP). This research recalculates the official TFP allocations using a more straightforward model that minimizes cost subject to nutrient constraints to establish a baseline for adult females and males. We then examine three additional diet plans to evaluate their feasibility under the current SNAP benefit allotment: a diet for lactose intolerance, for persons with type 2 diabetes, and a diet for pregnant women. The first model calculates a diet plan that contains no fluid milk, taking into account that 1 in 4 Americans is lactose intolerant. The second model calculates a diet plan that is lower in carbohydrates (grains and fruits comprise less than 45% of calories), reflecting a recommended diet for a person with type 2 diabetes, approximately 10% of the U.S. population. The third model includes the Institute of Medicine’s recommended diet for pregnancy. In each case, total daily cost per individual and allocation across food groups were compared. Our Lactose Intolerance, Type 2 Diabetes, and Pregnancy model for 20-50 year old females all return minimum food costs above the TFP budget allocation. This research demonstrates how the TFP provides an unrealistic assessment of need among 20-50 year old females with relatively common dietary needs. Results indicate that equalizing the TFP budget allocations between men and women would better accommodate the heterogeneous needs of America’s poorest individuals.

KEYWORDS:

• food security
• lactose intolerance
• type 2 diabetes
• pregnancy
• Supplemental Nutrition Assistance Program

Notes

1. Note that the natural logarithm of zero is undefined. Since the USDA’s objective function is logged, every food group allocation must be above zero for all age-sex groups.

2. Within the general U.S. population, 21% of Whites, 75% of Blacks and 51% of Hispanics are lactose intolerant (Wiley 2004, 2016). Given the ethnic composition of those on SNAP – 39% White, 26% Black and 11% Hispanic – lactose intolerance affects approximately 44% of those on SNAP (Gray, Fisher, and Lauffer 2006).

3. 39.8% of Americans are obese (CDC 2018b), and obesity rates are relatively higher among SNAP participants and low-income households (Delaney 2015).