G-48b Free Communication/Poster - Late-Breaking Abstracts Saturday, June 2, 2018, 7:30 AM - 11:00 AM Room: CC-Hall B
Epidemiological investigations have supported the healthy benefits of subsistence foods. Surprisingly, the health benefits derived from the nomadic nature of humans during the Paleolithic era have been understudied. Hunting and gathering activity that occurs far from the conveniences of civilization on public land most likely represent the closest example of this ancient lifestyle that thrived for thousands of years.
PURPOSE: To determine the energy demands, and changes in body composition and metabolic risk factors in humans during a 12-day wilderness hunting immersion.
METHODS: Four healthy men (age: 42±1 yr, BMI: 27±2 kg/m2) without any known cardiovascular, neurolological, pulmonary or metabolic pathology were recruited for participation in the study. Total energy expenditure (TEE) was measured using the doubly labeled water method and a written food diary was utilized to estimate total energy intake (TEI). Body composition was measured using dual energy x-ray absorptiometry; cross sectional area of the upper thigh (XT) and intrahepatic lipid (IHL) was measured using magnetic resonance imaging/spectroscopy. Fasted blood samples were collected for the measurement of total cholesterol (TC), high (HDL) and low-density lipoproteins (LDL). Results were analyzed using paired t-tests, presented as means±SEM and considered significant at P<0.05.
RESULTS: TEE and TEI were 4226±219 kcal/day and 2499±422 kcal/day, respectively, and resulted in a caloric deficit of 1726 kcal/day. There was a decrease in body weight (-3.2±0.2 kg), total fat mass (-3.1±0.1 kg) and visceral fat volume (-261±47 cm3). In contrast, total, leg and arm lean tissue mass and XT were preserved. There was a decrease in IHL (-0.5±0.1 % water peak). Beneficial trends were noted in blood lipids, but two of the four participants did not have their blood samples collected due to conflicts with weather and bush flight schedules.
CONCLUSION: In the context of a chronic caloric deficit, adipose tissue and IHL decreased without any reduction in lean tissue mass or muscle mass. These alterations may reflect the interactive influence of movement constancy and caloric deficit on the health benefits of the hunter-gatherer lifestyle.
Supported by NIH grant UL1GM118991, TL4GM118992, or RL5GM118990 and by a grant from the University of Montana.