No abstract

This paper honors the contributions made by Anthony (Tony) Sclafani and Karen Ackroff to both the Columbia University Seminar on Appetitive Behavior and to the field of ingestive behavior in general. We review their use of the progressive ratio (PR) licking paradigm, to determine whether the taste of sucrose, independent of its post-ingestive effects, is always positively reinforcing in animals. They demonstrated a monotonic increase in licking as concentration increased, and obtained results identical to those obtained with a lever-pressing paradigm, but licking was easier and more natural than lever pressing. The PR paradigm was translated to evaluate liquid food reward value in humans. An instrument (the sipometer) was devised that initially permitted a few seconds access to small amounts of a sweet beverage as the participants increased the time to obtain it in 3-5-sec increments. The device went through two refinements and currently delivers the reinforcer and measures the pressure exerted to obtain it. The sipometer is compared with other techniques for measuring motivation and reward. The use of the sipometer and the PR method are discussed in relation to the theoretical challenges inherent in measuring motivation and pleasure, from both psychological and behavioral economics perspectives, and why it is or is not important to separate these processes for both theoretical and practical applications.

The size of portions that people select is an indicator of underlying mechanisms controlling food intake. Fears of eating excessive portions drive down the sizes of portions patients with anorexia nervosa (AN) can tolerate eating significantly below those of healthy controls (HC) (Kissileff et al., 2016). To determine whether patients with AN will also reduce the sizes of typical or ideal portions below those of controls, ANOVA was used to compare maximum tolerable, typical, and ideal portions of four foods (potatoes, rice, pizza, and M&M's) in the same group of 24 adolescent AN patients and 10 healthy adolescent controls (HC), on which only the maximal portion data were previously reported. Typical and ideal portion sizes did not differ on any food for AN, but for HC, typical portions sizes (kcals) became larger than ideal as the energy density of the food increased, and were significant for the most energy dense food. Ideal portions of low energy dense foods were the same for AN as for in HC. There was a significant 3-way (group × food × portion type) interaction, such that HC selected larger maximum than typical portions only for pizza. We therefore proposed that individuals of certain groups, depending on the food, can be flexible in the amounts of food chosen to be eaten. We call this difference between maximum-tolerable, and typical portion sizes selected "elasticity." Elasticity was significantly smaller for AN patients compared to HC for pizza and was significantly inversely correlated with severity of illness. This index could be useful for clinical assessment of AN patients, and those with eating problems such as in obesity and bulimia nervosa and tracking their response to treatment.

The Eating Disorder Examination Interview Bariatric Surgery Version (EDE-BSV) assesses eating pathology after bariatric surgery but requires significant training and time to administer. Consequently, we developed a questionnaire format called the Eating Disorders After Bariatric Surgery Questionnaire (EDABS-Q). This study evaluates the consistency of responsiveness between the two formats. After surgery, 30 patients completed the EDE-BSV and EDABS-Q in a restricted randomized design. Patient reported behavior for each item which was converted to a score following the Eating Disorder Examination-Questionnaire (EDE-Q) scoring scheme. Responses fell into three distributions: (1) dichotomous, (2) ordinal, or (3) unimodal. Distributions of items were not different between the two formats and order did not influence response. Tests of agreement (normal approximation of the binomial test) and association (χ2 analyses on binary data and spearman rank order correlations on ordinal items) were performed. Percent concordance was high across items (63–100%). Agreement was significant in 31 of 41 items (Bonferroni-P < 0.001). Association was significant in 10 of 21 in χ2–appropriate items (Bonferroni-P < 0.002), and the ordinal items had highly significant correlations between formats (Bonferroni-P < 0.0125). The EDABS-Q is an adequate substitute for the EDE-BSV and may be useful for research and clinical evaluation of eating pathology after bariatric surgery.