Social disparities in food preparation behaviours: a DEDIPAC study

BACKGROUND: The specific role of major socio-economic indicators in influencing food preparation behaviours could reveal distinct socio-economic patterns, thus enabling mechanisms to be understood that contribute to social inequalities in health. This study investigated whether there was an independent association of each socio-economic indicator (education, occupation, income) with food preparation behaviours. METHODS: A total of 62,373 adults participating in the web-based NutriNet-Santé cohort study were included in our cross-sectional analyses. Cooking skills, preparation from scratch and kitchen equipment were assessed using a 0-10-point score; frequency of meal preparation, enjoyment of cooking and willingness to cook better/more frequently were categorical variables. Independent associations between socio-economic factors (education, income and occupation) and food preparation behaviours were assessed using analysis of covariance and logistic regression models stratified by sex. The models simultaneously included the three socio-economic indicators, adjusting for age, household composition and whether or not they were the main cook in the household. RESULTS: Participants with the lowest education, the lowest income group and female manual and office workers spent more time preparing food daily than participants with the highest education, those with the highest income and managerial staff (P < 0.0001). The lowest educated individuals were more likely to be non-cooks than those with the highest education level (Women: OR = 3.36 (1.69;6.69); Men: OR = 1.83 (1.07;3.16)) while female manual and office workers and the never-employed were less likely to be non-cooks (OR = 0.52 (0.28;0.97); OR = 0.30 (0.11;0.77)). Female manual and office workers had lower scores of preparation from scratch and were less likely to want to cook more frequently than managerial staff (P < 0.001 and P < 0.001). Women belonging to the lowest income group had a lower score of kitchen equipment (P < 0.0001) and were less likely to enjoy cooking meal daily (OR = 0.68 (0.45;0.86)) than those with the highest income. CONCLUSION: Lowest socio-economic groups, particularly women, spend more time preparing food than high socioeconomic groups. However, female manual and office workers used less raw or fresh ingredients to prepare meals than managerial staff. In the unfavourable context in France with reduced time spent preparing meals over last decades, our findings showed socioeconomic disparities in food preparation behaviours in women, whereas few differences were observed in men

Theoretical Studies on Peptidoglycans. II. Conformations of the Disaccharide-Peptide Subunit and the Three-Dimensional Structure of Ptidoglycan

Possible conformations of the disaccharide-peptide subunit of peptidoglycan (of Staphylococcus aureus or Micrococcus luteus) have been studied by an energy-minimization procedure. The favored conformation of the disaccharide N-acetyl-glucosaminyl-\beta (1-4)-N-acetylmuramic acid (NAG-NAM) is different from that of cellulose or chitin; this disagrees with the assumption of earlier workers. The disaccharide-peptide subunit favors three types of conformations, among which two are compact and the third is extended. All these conformations are stabilized by intramolecular hydrogen bonds. Based on these conformations of the subunit, two different models are proposed for the three-dimensional arrangement of peptidoglycan in the bacterial cell wall

Theoretical Studies on Peptidoglycans. II. Conformations of the Disaccharide-Peptide Subunit and the Three-Dimensional Structure of Ptidoglycan

Possible conformations of the disaccharide-peptide subunit of peptidoglycan (of Staphylococcus aureus or Micrococcus luteus) have been studied by an energy-minimization procedure. The favored conformation of the disaccharide N-acetyl-glucosaminyl-\beta (1-4)-N-acetylmuramic acid (NAG-NAM) is different from that of cellulose or chitin; this disagrees with the assumption of earlier workers. The disaccharide-peptide subunit favors three types of conformations, among which two are compact and the third is extended. All these conformations are stabilized by intramolecular hydrogen bonds. Based on these conformations of the subunit, two different models are proposed for the three-dimensional arrangement of peptidoglycan in the bacterial cell wall

Theoretical Studies on Peptidoglycans. I. Effect of L-Alanyl, D-Butyl, or D-Valyl Residues at the Positions 4 or 5 of the Pentapeptide Moiety of Peptidoglycan on the Cross-Linking Reaction

Possible conformations of $X-D-alany^{l4}-D-alanine^5$ and its analogs $X-L-analy^{l4}-D-alanine^5 X-D-alany^{l4}-L-alanine^5, X-D-buty^{l4}-D-alanine^5, X-D-alany^{l4}-D-butyric acid^5, X-D-valy^{l4}-D-alanine^5, and X-D-alany^{l4}-D-valine^5$ have been analyzed by theoretical methods. These studies suggest that L-alanine and D-valine at the 4 or 5 postion of the pentapeptide moiety of peptidoglycan will drastically reduce the cross-linking in peptidoglycan biosynthesis, whereas the effect of D- butyric acid will be marked at the 4 postition and modeate at the 5 position. This is in good agreement with experimental results. The cross-linking enzyme transpeptidase requires a specific confroamation for the 4th and 5th residues for optimal binding

Theoretical studies on peptidoglycans. II. Conformations of the disaccharide-peptide subunit and the three-dimensional structure of peptidoglycan

Possible conformations of the disaccharide-peptide subunit of peptidoglycan (of Staphylococcus aureus or Micrococcus luteus) have been studied by an energy-minimization procedure. The favored conformation of the disaccharide N-acetyl-glucosaminyl-β (1-4)-N-acetylmuramic acid (NAG-NAM) is different from that of cellulose or chitin; this disagrees with the assumption of earlier workers. The disaccharide-peptide subunit favors three types of conformations, among which two are compact and the third is extended. All these conformations are stabilized by intramolecular hydrogen bonds. Based on these conformations of the subunit, two different models are proposed for the three-dimensional arrangement of peptidoglycan in the bacterial cell wall

Theoretical studies on peptidoglycans. I. Effect of L-alanyl, D-butyl, or D-valyl residuces at the positions 4 or 5 of the pentapeptide moiety of peptidoglycan on the cross-linking reaction

Possible conformations of X-D-alanyl4-D-alanine5 and its analogs X-L-analyl4-D-alanine5 X-D-alanyl4-L-alanine5, X-D-butyl4-D-alanine5, X-D-alanyl4-D-butyric acid5, X-D-valyl4-D-alanine5, and X-D-alanyl4-D-valine5 have been analyzed by theoretical methods. These studies suggest that L-alanine and D-valine at the 4 or 5 postion of the pentapeptide moiety of peptidoglycan will drastically reduce the cross-linking in peptidoglycan biosynthesis, whereas the effect of D- butyric acid will be marked at the 4 postition and modeate at the 5 position. This is in good agreement with experimental results. The cross-linking enzyme transpeptidase requires a specific confroamation for the 4th and 5th residues for optimal binding

Theoretical studies on β-lactam antibiotics: I. Conformational similarity of penicillins and cephalosporins to X-D-alanyl-D-alanine and correlation of their structure with activity

The substrate analogue hypothesis proposed for the mechanism of the action of penicillins and cephalosporins is examined by stereochemical criteria. These β-lactam antibiotics assume conformation similar to X-D-alanyl-D-alanine due to the presence of the lactam ring; this disagrees with the assumption made by Tipper &amp;Strominger that L and D amino acid residues take similar conformation. The model proposed in this study for the activity of these antibiotics differs considerably from the earlier models, mainly in φ2 rotational angle which determines the conformation of the aminoacyl group. The inactivity of C6 or C7 epimers and the effect of various substitutions at 6α or 7α and C2 positions of penicillins and cephalosporins on the biological activity are explained