A history of PAs in the US Public Health Service.

Since 1798, the men and women of the Commissioned Corps of the US Public Health Service (USPHS), one of the seven US uniformed services, have served on the front lines of public health. Two hundred years after the start of the USPHS, the first physician assistant (PA) entered the service to carry on the tradition of protecting, promoting, and advancing the health and safety of the nation. These dedicated clinicians are involved in healthcare delivery to underserved and vulnerable populations, disease control and prevention, biomedical research, food and drug regulation, and national and international response efforts for natural and man-made disasters. This article describes how PAs in the Commissioned Corps of the USPHS have impacted the health and safety of not only the United States but also the international community.

Energy Expenditure Responses to Fasting and Overfeeding Identify Phenotypes Associated With Weight Change.

Because it is unknown whether 24-h energy expenditure (EE) responses to dietary extremes will identify phenotypes associated with weight regulation, the aim of this study was to determine whether such responses to fasting or overfeeding are associated with future weight change. The 24-h EE during energy balance, fasting, and four different overfeeding diets with 200% energy requirements was measured in a metabolic chamber in 37 subjects with normal glucose regulation while they resided on our clinical research unit. Diets were given for 24 h each and included the following: (1) low protein (3%), (2) standard (50% carbohydrate, 20% protein), (3) high fat (60%), and (4) high carbohydrate (75%). Participants returned for follow-up 6 months after the initial measures. The decrease in 24-h EE during fasting and the increase with overfeeding were correlated. A larger reduction in EE during fasting, a smaller EE response to low-protein overfeeding, and a larger response to high-carbohydrate overfeeding all correlated with weight gain. The association of the fasting EE response with weight change was not independent from that of low protein in a multivariate model. We identified the following two independent propensities associated with weight gain: a predilection for conserving energy during caloric and protein deprivation and a profligate response to large amounts of carbohydrates.

Short-term isocaloric manipulation of carbohydrate intake: effect on subsequent ad libitum energy intake.

BACKGROUND: Isocaloric manipulation of carbohydrate or fat intake could alter subsequent ad libitum food intake. METHODS: In a controlled inpatient study, we investigated whether isocaloric manipulation of carbohydrate or fat would alter subsequent ad libitum energy intake. Eighteen non-diabetic subjects (age range 19-53 years.; 15 M/3F; % body fat 38.5 ± 9.1 (mean ± SD)) were fed for 3 days an isocaloric high-carbohydrate diet (HC; 60% carbohydrate, 20% fat, 20% protein) and a high-fat diet (HF; 50% fat, 30% carbohydrate, 20% protein) in random order each followed by 3 days of ad libitum food intake. RESULTS: There were no differences in mean daily energy intake (EI) following each diet (HC vs. HF: 4,811 ± 1,190 vs. 4,823 ± 1,238 kcal/d; P = 0.7) or in the percent of weight maintenance energy needs (%EN-WM; 173 ± 41 vs. 173 ± 46%, P = 0.5). However, the individual difference in EI between the HF versus HC diet (ΔEI) both on day one and over the 3 days of each ad libitum period was negatively associated with % body fat (%BF) and waist circumference (day 1: ΔEI vs. %BF, r = -0.49, P = 0.04; mean day 1-3 kcal ΔEI vs. %BF, r = -0.66, P = 0.003, and ΔEI vs. waist, r = -0.65, P = 0.004). CONCLUSIONS: A short-term isocaloric HC diet did not result in overall lower EI compared with a HF diet in the same individuals. However, we did find that increasing body fat was associated with less decline in EI following the HC versus HF diet indicating that increasing adiposity is associated with altered regulation of EI in response to macronutrient changes.