Genetic and environmental contributions to food use patterns of young adult twins

Abstract

The contribution of genetic factors to individual differences in food use was estimated in a large population-based twin cohort of young adults (22-to 27-year-old). Male and female twins (n=2009 complete twin pairs) evaluated use-frequencies of 24 food items using 5 categories (1=never -5=several times a day) in a postal questionnaire. Foods were categorized by factor analysis. Estimates of the relative proportions of additive genetic, shared environmental, and unshared environmental effects on the use-frequency of food items and factor scores were obtained by quantitative genetic modeling of twin data based on linear structural equations. Four factors of food use were identified: "healthy" foods, high-fat foods, sweet foods, and meats. The variance of the use-frequency of food items and food categories was explained by additive genetic and unshared environmental influences, whereas shared environmental factors did not contribute to food use. The average proportions of genetic effects on the total variance of the use-frequency of food items and food categories were 40% and 45%, respectively. Sex differences were observed in the magnitude of genetic influences for use-frequency of four food items (chocolate, other sweets, fried foods, and meat), and in genetic factors underlying the use of three (fresh vegetables, fruits, and cheeses) items. In conclusion, family environment does not appear to influence the food use of young adults and thus nutritional education should be targeted at this age group to support development of healthy eating patterns. In addition, the results illuminate the importance of the sex-specific genetic effects on food use.

The genetic and environmental influences on childhood obesity: a systematic review of twin and adoption studies

“…The role of common environmental factors on food preferences has been found to be substantial in young children, 40 but this effect disappears in young adulthood when eating behavior and food preferences are determined solely by additive genetic and specific environmental factors. 41,42 Similarly, shared environmental effects are found on childhood physical activity and exercise patterns, 43 but weaken during adolescence 44 and are virtually absent in young adulthood. 45 The effect of childhood home environment thus seems to diminish when children become older and become more independent to make their own choices.…”

Genetic and environmental influences on nutrient intake

“…Indeed, in children aged 4-5 years, strong shared environmental influences on preference and use-frequency has been reported for desserts (62 %), vegetables (46 %), and fruits (32 %), while non-shared environmental effects are low across all food groups (10-18 %) (Breen et al 2006). This significance of the shared environment most likely reflects the limited exposure children have to important food encounters away from home at such a young age, since similar studies in adults aged 22-27 (Keskitalo et al 2008) and over 50 (van den Bree et al 1999) suggest a disappearance of this shared environmental effect after childhood. Indeed, Faith et al (2008) have more recently supported the notion that the shared family environment can influence short-term eating patterns, and another recent study found that the shared environment can strongly influence the consumption of certain food groups, such as fruits and vegetables (40-46 %), without having any influence on total daily energy or macronutrient intake (Hasselbalch et al 2008).…”

“…Evidence for heritable influences on food consumption (Breen et al 2006;Keskitalo et al 2008;Hasselbalch et al 2008;van den Bree et al 1999) and energy and macronutrient intake (de Castro 1993;Faith et al 1999;Hasselbalch et al 2008;Hur et al 1998) is compelling. The magnitude of genetic effects is heterogeneous among studies; they generally explain about 20-40 % of the variance in energy and macronutrient intake (Rankinen and Bouchard 2006).…”

Leisure-time physical activity and nutrition: a twin study

“…Because there were more similarities than differences in the co-twins' eating behaviours (see Tables 3 and 4), it seems that genes may have an effect on eating behaviours as proposed earlier (31) . However, as twin pairs have a shared childhood family environment and the lifestyles of co-twins usually show greater similarity than those of other individuals, it seems that the differences in physical activity and dietary habits observed in the present study may have a causal relationship.…”