Closing the Meal Gap Act of 2019 This bill revises the requirements for calculating Supplemental Nutrition Assistance Program (SNAP, formerly known as the food stamp program) benefits. Specifically, the bill increases the minimum SNAP benefit and requires that benefits be calculated using a low-cost food plan (i.e., the diet required to feed a family of four); directs the Department of Agriculture (USDA) to determine the requirements for the low-cost food plan; requires USDA to make adjustments to the plan to account for household size, changes in the cost of the diet, and the costs of food in specified areas; revises the amounts authorized for nutrition assistance block grants for Puerto Rico and American Samoa and requires that the amounts be modified based on adjustments to the low-cost food plan; modifies the requirements for calculating household income to determine SNAP eligibility by authorizing a standard medical expense deduction for households containing an elderly or disabled member and eliminating the cap on the deduction for excess shelter expenses; and revises eligibility requirements under SNAP for certain students enrolled in institutions of higher education.