Two Days of Calorie Deprivation Induced by Underfeeding and Aerobic Exercise Degrades Mood and Lowers Interstitial Glucose but Does Not Impair Cognitive Function in Young Adults.
In studies assessing the effects of acute undernutrition on cognitive function, volunteers are sedentary and findings are equivocal, even though glucose concentrations fall substantially. However, military personnel and endurance athletes often are underfed when physical demands, and consequently energy expenditure, are substantial.



The objective of this study was to determine whether 2 d of near-total calorie deprivation combined with aerobic exercise degraded cognitive performance and mood.



A double-blind, placebo-controlled, crossover design was used. Twenty-three volunteers [17 men (mean ± SD age: 20.5 ± 0.7 y) and 6 women (mean ± SD age: 23.3 ± 1.4 y); mean ± SD body mass index (in kg/m2): 25 ± 3] participated for 68 h, including a 51-h inpatient phase in a calorie-deprived or fully fed state during which behavioral testing was conducted and interstitial glucose was monitored continuously. Mood and cognitive performance, including psychomotor and visual vigilance, visual match-to-sample, repeated acquisition (motor learning), N-back (working memory), and grammatical reasoning, were repeatedly assessed. During each condition, individual daily energy intake and expenditure were controlled. During calorie deprivation, volunteers consumed 266 ± 61 kcal/d; during full feeding, they consumed 3935 ± 769 kcal/d. Participants engaged in identical exercise sessions for 4 h/d at 40-65% of peak volume of oxygen uptake attained.



Calorie deprivation did not affect any aspect of cognitive performance, but produced robust effects on mood measured by the Profile of Mood States, including increased tension (P < 0.001), fatigue (P < 0.001), and total mood disturbance (from -0.80 ± 5.1 to 20.1 ± 6.1; P < 0.001), and decreased vigor (P = 0.002), as indicated by treatment × trial (time) effects on ANOVA. Interstitial glucose concentrations were lower during calorie deprivation than in the fully fed condition (P = 0.002, treatment × trial interaction) and declined to 61 mg/dL by the end of the treatment condition.



In healthy young men and women, 2 d of severe calorie deprivation in combination with substantial aerobic exercise adversely affects multiple aspects of mood, but not cognition, in spite of substantial reductions in interstitial glucose concentrations. This trial was registered at clinicaltrials.gov as NCT01603550.
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA; harris.r.lieberman.civ@mail.mil.
Harris R
HR
Lieberman
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA.
Asma S
AS
Bukhari
Oak Ridge Associated Universities, Oak Ridge, TN; and.
John A
JA
Caldwell
Oak Ridge Associated Universities, Oak Ridge, TN; and.
Marques A
MA
Wilson
Warfighter Science Technology and Applied Research, Natick Soldier Research, Development and Engineering Center, Natick, MA.
Caroline R
CR
Mahoney
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA.
Stefan M
SM
Pasiakos
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA.
James P
JP
McClung
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA.
Tracey J
TJ
Smith
D000328:Adult; D000339:Affect; D001786:Blood Glucose; D003071:Cognition / Q000502:physiology; D004311:Double-Blind Method; D002149:Energy Intake; D015444:Exercise / Q000502:physiology*; D005260:Female; D005508:Food Deprivation; D006801:Humans; D008297:Male; D055815:Young Adult
D001786:Blood Glucose
POMS; depression; fatigue; reasoning; vigilance; working memory