Replacing Dairy Fat With Polyunsaturated and Monounsaturated Fatty Acids: A Food-Level Modeling Study of Dietary Nutrient Density and Diet Quality Using the 2013-16 National Health and Nutrition Examination Survey

The Dairy Matrix: Its Importance, Definition, and Current Application in the Context of Nutrition and Health

Nutrition research has shifted from single nutrients to examining the association of foods and dietary patterns with health. This includes recognizing that food is more than the sum of the individual nutrients and relates to the concept of the food matrix. Like other foods, dairy foods are characterized by their unique matrices and associated health effects. Although the concepts of the food matrix and/or dairy matrix are receiving increasing attention in the nutrition and health literature, there are different terms and definitions that refer to it. This article aims to provide insights into the application of the concepts of the food matrix and dairy matrix and to provide a current overview of the definitions and terminology surrounding the food matrix and dairy matrix. By analysing these aspects, we aim to illustrate the practical implications of the food matrix and dairy matrix on nutrition and health outcomes and evaluate their roles in shaping evidence-based policies for the benefit of public health. There is a need for harmonized definitions within the literature. Therefore, the International Dairy Federation put forward harmonized terms to be internationally applicable: the "dairy matrix" describes the unique structure of a dairy food, its components (e.g., nutrients and non-nutrients), and how they interact; "dairy matrix health effects" refers to the impact of a dairy food on health that extend beyond its individual components.

Whole-Milk Dairy Foods: Biological Mechanisms Underlying Beneficial Effects on Risk Markers for Cardiometabolic Health

Lifestyle modifications that include adherence to healthy dietary patterns that are low in saturated fat have been associated with reduced risk for cardiovascular disease, the leading cause of death globally. Whole-milk dairy foods, including milk, cheese, and yogurt, are leading sources of saturated fat in the diet. Dietary guidelines around the world recommend the consumption of low-fat and fat-free dairy foods to obtain overall healthy dietary patterns that help meet nutrient recommendations while keeping within recommended calorie and saturated fat limitations. A body of observational and clinical evidence indicates, however, that whole-milk dairy food consumption, despite saturated fat content, does not increase the risk for cardiovascular disease. This review describes the proposed biological mechanisms underlying inverse associations between whole-milk dairy food consumption and risk markers for cardiometabolic health, such as altered lipid digestion, absorption, and metabolism; influence on the gut microflora; and regulation of oxidative stress and inflammatory responses. The dairy food matrix, a term used to describe how the macronutrients and micronutrients and other bioactive components of dairy foods are differentially packaged and compartmentalized among fluid milk, cheese, and yogurt, may dictate how each affects cardiovascular risk. Current evidence indicates consideration of dairy foods as complex food matrices, rather than delivery systems for isolated nutrients, such as saturated fatty acids, is warranted.

Consumption of Key Food Groups by Individuals Consuming Popular Diet Patterns: Mixed Effects of Replacing Foods High in Added Sugar, Sodium, Saturated Fat, and Refined Grains

Adults in the United States are increasingly following 'popular' diet patterns that restrict food groups, macronutrients, or eating time. However, the intake of food groups associated with these diet patterns has not been well characterized. The objectives of this study were to (1) characterize the mean intake of food groups among consumers of popular diet patterns in the US, and (2) model the effect of targeted food substitutions on the intake of food groups. Data were acquired from the National Health and Nutrition Examination Survey, 2005-2018 (n = 34,411). A diet model was developed to assess the effects of replacing one serving each of foods highest in added sugar, sodium, saturated fat, and refined grains with healthy alternatives on the intake of key food groups for each diet pattern. Modeled replacement resulted in increased intake of fruit and whole grains and decreased intake of dairy for most diet patterns, while the effects on the intake of vegetables, protein foods, and oils were variable across diet patterns. The complexity of the natural eating environment, in which many people consume mixed dishes that include both healthy and less healthy ingredients, produces a challenge for health professionals when providing dietary counseling. Nevertheless, this substitution approach may help improve adherence to dietary guidelines, especially if used as a steppingstone for further dietary improvement.

MUFA in metabolic syndrome and associated risk factors: is MUFA the opposite side of the PUFA coin?

Omega-9 fatty acids represent some of the main mono-unsaturated fatty acids (MUFA) found in plant and animal sources. They can be synthesized endogenously in the human body, but they do not fully provide all the body's requirements. Consequently, they are considered as partially essential fatty acids. MUFA represent a healthier alternative to saturated animal fats and have several health benefits, including the prevention of metabolic syndrome (MetS) and its complications. This review concentrates on the major MUFA pharmacological activities in the context of MetS management, including alleviating cardiovascular disease (CVD) and dyslipidemia, central obesity, non-alcoholic fatty liver disease (NAFLD), and type 2 diabetes mellitus (T2DM). The beneficial effects of MUFA for CVD were found to be consistent with those of polyunsaturated fatty acids (PUFA) for the alleviation of systolic and diastolic blood pressure and high low density lipoprotein cholesterol (LDLc) and triacylglcerol (TAG) levels, albeit MUFA had a more favorable effect on decreasing night systolic blood pressure (SBP). To reduce the obesity profile, the use of MUFA was found to induce a higher oxidation rate with a higher energy expenditure, compared with PUFA. For NAFLD, PUFA was found to be a better potential drug candidate for the improvement of liver steatosis in children than MUFA. Any advantageous outcomes from using MUFA for diabetes and insulin resistance (IR) compared to using PUFA were found to be either non-significant or resulted from a small number of meta-analyses. Such an increase in the number of studies of the mechanisms of action require more clinical and epidemiological studies to confirm the beneficial outcomes, especially over a long-term treatment period.

The New Hybrid Nutrient Density Score NRFh 4:3:3 Tested in Relation to Affordable Nutrient Density and Healthy Eating Index 2015: Analyses of NHANES Data 2013-16

Background: Hybrid nutrient density scores are based on both nutrients and selected food groups. Objective: To compare the new hybrid nutrient-rich food NRFh 4:3:3 score to other nutrient-rich food (NRF) scores, energy density, and energy cost and to model the impact on the Healthy Eating Index (HEI-2015) of partially replacing less nutrient-rich with more nutrient-rich foods. Methods: Analyses were based on 5870 foods and beverages in the Food and Nutrient Database for Dietary Studies and on 24 h dietary recalls from the National Health and Nutrition Examination Survey (NHANES 2013–16). The NRFh 4:3:3 model was based on four nutrients to encourage (protein fiber, potassium, MUFA + PUFA); three food groups to encourage (dairy, fruit, whole grains); and three nutrients to limit (saturated fat, added sugar, sodium). Ratings generated by NRFh 4:3:3 and by other NRF models were correlated with score components, energy density (kcal/100 g), and energy cost (USD/100 kcal). The impact on HEI-2015 of replacing foods in the lowest nutrient density tertile (T1) with top tertile (T3) foods at 10%, 20%, 30%, and 100% equicaloric replacement was modeled using NHANES 2013–16 dietary data by population subgroups. Results: The NRFh 4:3:3 model awarded higher scores to foods containing dairy, fruit, and whole grains and proportionately lower scores to vegetables when compared to the NRF 9.3 model. Higher NRF and NRFh nutrient density scores were linked to lower energy density and higher energy cost; however, both correlations were lower for the NRFh 4:3:3. Isocaloric replacement of bottom tertile with top tertile foods as rated by both models led to significantly higher HEI-2105 values, based on complete (100%) and on partial (10–30%) replacement. Conclusion: The new NRFh 4:3:3 model provides the basis for developing new metrics of affordable nutrient density. The model identified “best value” food categories that were both affordable and nutrient-rich. Total and partial replacement of low nutrient density with high nutrient density foods was associated with higher HEI-2015 scores, suggesting that even partial inclusion of more nutrient dense foods in the diet may have an important impact on total diet quality.

Does stress attenuate motivation for healthful eating in pregnancy and postpartum?

Despite high motivation for healthful eating during pregnancy, maternal diet quality is inadequate. During pregnancy, women may relax effortful control over eating to reduce stress; thus, stress may override motivation to eat healthfully. This secondary analysis of data from the Pregnancy Eating Attributes Study longitudinal cohort investigated associations of motivation for healthful eating and perceived stress with diet quality during pregnancy (n = 365) and postpartum (n = 266), and investigated whether stress modifies associations of motivation with diet quality. Women (M_age = 31.3; gestational age ≤ 12 weeks) were recruited from the Chapel Hill, North Carolina area and completed multiple 24-h diet recalls (once each trimester of pregnancy, and at 4-6 weeks, 6 months, and 1 year postpartum) and validated measures of perceived stress and motivation for healthful eating (autonomous and controlled). Hierarchical multiple regressions tested associations of diet quality (Healthy Eating Index-2015) with stress, motivation, and their interactions. Additionally, themes extracted from previously-analyzed focus groups conducted with a subsample of participants were re-examined for content relevant to stress, motivation, and diet. Pregnancy and postpartum diet quality was positively associated with autonomous motivation, but was unassociated with controlled motivation and stress. Interaction terms did not appreciably improve model fit. Focus group participants described both internal and external forces contributing to their motivation for healthy eating during pregnancy and described the impact of stress on eating behaviors through amplification of food cravings. Future research is needed to identify influences on maternal motivation for healthful eating.

Dietary saturated fat and heart disease: a narrative review

The American Heart Association (AHA) recently published a meta-analysis that confirmed their 60-year-old recommendation to limit saturated fat (SFA, saturated fatty acid) and replace it with polyunsaturated fat to reduce the risk of heart disease based on the strength of 4 Core Trials. To assess the evidence for this recommendation, meta-analyses on the effect of SFA consumption on heart disease outcomes were reviewed. Nineteen meta-analyses addressing this topic were identified: 9 observational studies and 10 randomized controlled trials. Meta-analyses of observational studies found no association between SFA intake and heart disease, while meta-analyses of randomized controlled trials were inconsistent but tended to show a lack of an association. The inconsistency seems to have been mediated by the differing clinical trials included. For example, the AHA meta-analysis only included 4 trials (the Core Trials), and those trials contained design and methodological flaws and did not meet all the predefined inclusion criteria. The AHA stance regarding the strength of the evidence for the recommendation to limit SFAs for heart disease prevention may be overstated and in need of reevaluation.