Low carbohydrate, high fat diet increases C-reactive protein during weight loss.
OBJECTIVE
Chronic inflammation is associated with elevated risk of heart disease and may be linked to oxidative stress in obesity. Our objective was to evaluate the effect of weight loss diet composition (low carbohydrate, high fat, LC or high carbohydrate, low fat, HC) on inflammation and to determine whether this was related to oxidative stress.


METHODS
Twenty nine overweight women, BMI 32.1 +/- 5.4 kg/m(2), were randomly assigned to a self-selected LC or HC diet for 4 wks. Weekly group sessions and diet record collections helped enhance compliance. Body weight, markers of inflammation (serum interleukin-6, IL-6; C-reactive protein, CRP) oxidative stress (urinary 8-epi-prostaglandin F2alpha, 8-epi) and fasting blood glucose and free fatty acids were measured weekly.


RESULTS
The diets were similar in caloric intake (1357 kcal/d LC vs. 1361 HC, p=0.94), but differed in macronutrients (58, 12, 30 and 24, 59, 18 for percent of energy as fat, carbohydrate, and protein for LC and HC, respectively). Although LC lost more weight (3.8 +/- 1.2 kg LC vs. 2.6 +/- 1.7 HC, p=0.04), CRP increased 25%; this factor was reduced 43% in HC (p=0.02). For both groups, glucose decreased with weight loss (85.4 vs. 82.1 mg/dl for baseline and wk 4, p<0.01), while IL-6 increased (1.39 to 1.62 pg/mL, p=0.04). Urinary 8-epi varied differently over time between groups (p<0.05) with no consistent pattern.


CONCLUSIONS
Diet composition of the weight loss diet influenced a key marker of inflammation in that LC increased while HC reduced serum CRP but evidence did not support that this was related to oxidative stress.
Rankin
Janet W
JW
Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061-0430, USA. jrankin@vt.edu
Turpyn
Abigail D
AD
D000328:Adult; D002097:C-Reactive Protein / Q000009:adverse effects / Q000032:analysis*; D050528:Diet, Carbohydrate-Restricted; D018752:Diet, Fat-Restricted; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D002149:Energy Intake / Q000502:physiology; D005260:Female; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy*; D018384:Oxidative Stress; D012307:Risk Factors; D016896:Treatment Outcome; D015431:Weight Loss / Q000502:physiology*
D004040:Dietary Carbohydrates; D004041:Dietary Fats; D002097:C-Reactive Protein