Low-grade inflammation and daily life food-related motivation in obesity

Obesity is associated with low-grade inflammation, which – our prior work shows – causally and reversibly increases effort aversion and related brain responses during food-related decision-making. However, how these laboratory findings translate to daily-life (food) motivation remains unclear. This study investigated low-grade inflammation in more ecologically valid measures of (food-related) motivation in obesity.

We conducted a cross-sectional study (N=145 women, BMI>27 kg/m2, 18-59 yrs) and a 12-week randomized controlled trial (N=57 women, BMI>30 kg/m2, 18-59 years, C-reactive protein (CPR)>3 mg/l) testing the anti-inflammatory drug colchicine versus placebo. We measured effort-related food intake using a bogus taste test, daily-life motivation using ecological momentary assessment (EMA), and dietary intake using a food frequency questionnaire (FFǪ).

INFLA-score (CRP, white blood cell count, neutrophil-to-lymphocyte ratio, platelets) related to lower intake of high-effort food items on the taste test (β –0.26 SD, p=0.011), lower engagement in high-effort activities (OR 0.72, p<0.001), and negatively moderated the association between anticipation and activity completion in EMA (OR 0.89, p=0.032). On the FFǪ, INFLA-score related to lower intake of legumes and fruits and more intake of processed meat (all p<0.05). Colchicine decreased overall caloric intake (β –341 kcal, p=0.018). A decrease in inflammation related to healthier dietary choices (Spearman ρ=0.37, p=0.013). Colchicine did not affect effort-related food intake on the taste test or EMA.

These findings indicate that that obesity-related inflammation is associated with increased effort-related food intake and motivation in daily life, and that reducing inflammation decreases (unhealthy) food intake. Such effects may partly underlie the challenges of achieving and maintaining weight loss.