## 2 Materials and Methods
### Data Collection  
Dietary Assessment: The Diet History Questionnaire (DHQIII) is a validated food frequency questionnaire [36] and was used to assess diet intake at a baseline (pre-intervention) and one month post-intervention (within +1 week) to capture sustained dietary changes after the cooking class. The DHQIII generates absolute intake values based on the average intake of energy, 219 nutrients, dietary constituents, and food groups. The results from the DHQIII were reviewed and analyzed for total dietary intake of kilocalories (kcal), total fiber (grams), and the main sources of fiber-rich foods of fruits (cup/day), vegetables (cup/day), whole grains (oz/day), nuts and seeds (oz/day), and legumes (oz/day). These dietary components were chosen for analysis based on the key principles of education included in the cooking class.  
Dietary Inflammatory Index (DII): From the DHQIII, DII scores were calculated. The DII has been previously validated with various inflammatory markers and has been used in several cancer populations [37; 38; 39]. A complete description of the DII scoring system has been previously published [31]. The DII includes up to 45 food parameters with individual inflammatory effect scores, which are summed for an overall DII score for each participant.  
Valid DII scores typically contain at least 25-30 parameters [40]. For the present study, a total of 30 parameters were available from the DHQIII for score calculation (Table 1). In this study, energy-adjusted DII (E-DII(tm) scores were calculated for each participant to account for caloric intake in relation to the amount of nutrients consumed. E-DII scores are calculated per 1000 calories of food consumed, utilizing the energy-standardized version of the world database used to calculate the food effect scores [40]. Possible DII scores range from \(-8.87\) to 7.98, where a higher, more positive, E-DII score designates a more pro-inflammatory diet, whereas smaller, more negative E-DII values indicate more anti-inflammatory diets. In this analysis, the change in E-DII scores was the primary outcome.  
Cognitive Assessment: The secondary outcomes examined were the Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) sub-scores, as the measure of subjective cognitive impairment assessment. The FACT-Cog was administered electronically at baseline and one-month post-intervention (within +1 week). The FACT-Cog includes 37 items assessing cognitive function across four scales: perceived cognitive impairments (COG-PCI; 20 items; 0-72 score range), impact on quality of life (COG-QOL; 4 items; 0-16 score range), comments from others (COG-OTH; 4 items; 0-16 score range), and perceived cognitive abilities (COG-PCA; 9 items; 0-28 score range) [41; 42]. Participants are asked to respond how frequently, on a scale of 0-4, they experienced various symptoms in the previous seven days. Items are summed to calculate scores for each sub-scale. The average time for completion is 10-15 min. The FACT-Cog sub-scores, COG-PCI, COG-QOL, COG-OTH, and COG-PCA, were analyzed, and the COG-PCI was considered the primary score [42; 43; 44]. The higher the score, the better the cognitive function, as well as the lower the impact on the patients' quality of life [45].