Publications by authors named "Manabu T Nakamura"

Background: Online weight loss programs have ambiguous efficacy. There is a growing body of evidence that weight loss programs when combined with apps have better outcomes; however, many apps lack an evidence-based approach to dietary changes for weight loss and do not rely on a theoretical framework for behavior change.

Objective: This study aimed to describe the development and the preliminary usability and acceptability testing of a web app that uses behavior change techniques (BCTs) to support users of a comprehensive online weight loss program.

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Background: The purpose of this intervention was to investigate the feasibility, acceptability, and preliminary effectiveness of an online weight loss program, EMPOWER, in rural, underserved communities.

Methods: Adults with a body mass index (BMI) ≥ 25 kg/m living in rural counties were recruited through collaboration with University of Illinois Extension. The intervention lasted 1 year including online educations sessions, nutrition and lifestyle coaching, and diet and weight monitoring a novel web application, MealPlot.

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Article Synopsis
  • The study investigates the role of omega-3 fatty acids, specifically EPA and DHA, in reducing liver fat storage while examining the lesser-known effects of ALA on liver metabolism.
  • Male mice were fed different diets (lard, flaxseed oil, or menhaden oil) for 21 weeks, and various tests were conducted to analyze fat composition and gene expression related to fat metabolism.
  • Results showed that EPA/DHA from menhaden oil significantly lowered liver fat compared to lard and flax diets, and the beneficial effects on liver fat regulation were independent of the D6D enzyme activity linked to ALA.
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Background: Currently available behavioral and dietary weight-loss programs lack magnitude and sustainability compared with bariatric surgery. A novel dietary weight-loss program was developed to assist participants in achieving sustainable diet changes by building knowledge and skills in food self-selection. Although the approach worked, a large variation was observed in outcome among participants.

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The Δ-6 desaturase (D6D) enzyme is not only critical for the synthesis of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from α-linolenic acid (ALA), but recent evidence suggests that it also plays a role in adipocyte lipid metabolism and body weight; however, the mechanisms remain largely unexplored. The goal of this study was to investigate if a D6D deficiency would inhibit triacylglycerol storage and alter lipolytic and lipogenic pathways in mouse white adipose tissue (WAT) depots due to a disruption in EPA and DHA production. Male C57BL/6J D6D knockout (KO) and wild-type (WT) mice were fed either a 7% w/w lard or flax (ALA rich) diet for 21 weeks.

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Delta-6 desaturase (D6D), encoded by the gene, catalyzes the first step in the conversion of α-linolenic acid to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The ablation of D6D in whole body knockout (KO) mice results in an inability to endogenously produce EPA and DHA. Evidence supports a beneficial role for EPA and DHA on insulin-stimulated glucose disposal in skeletal muscle in the context of a metabolic challenge; however, it is unknown how low EPA and DHA levels impact skeletal muscle fatty acid composition and insulin signaling in a healthy context.

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Obesity is a significant contributor to the development of chronic diseases, some of which can be prevented or reversed by weight loss. However, dietary weight loss programs have shortcomings in the success rate, magnitude, or sustainability of weight loss. The Individualized Diet Improvement Program's (iDip) objective was to test the feasibility of a novel approach that helps individuals self-select a sustainable diet for weight loss and maintenance instead of providing weight loss products or rigid diet instructions to follow.

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Polyunsaturated fatty acids (PUFAs), especially arachidonic acid (ARA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), play an important role in biological regulation. In our previous study using mice deficient in Δ6 desaturase (D6D), we reported that ARA is required for body growth, while DHA is necessary for functional development. In mammals, ARA and DHA are supplied directly or by synthesis from linoleic acid (LA) and α-linolenic acid (ALA).

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Intrauterine growth restriction is a common cause of small for gestational age (SGA) infants worldwide. SGA infants are deficient in digestive enzymes required for fat digestion and absorption compared to appropriate for gestational age (AGA) infants, putting them at risk for impaired neurocognitive development. The objective was to determine if a hydrolyzed fat (HF) infant formula containing soy free fatty acids, 2-monoacylglycerolpalmitate, cholesterol, and soy lecithin could increase brain tissue incorporation of essential fatty acids or white matter to enhance brain development in SGA and AGA neonatal piglet models.

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Delta-6 desaturase (D6D), which is encoded by the fatty acid desaturase (Fads2) gene, is the rate-limiting enzyme for the endogenous production of n-3 long-chain polyunsaturated fatty acids. The absence of D6D activity in Fads2 knockout mice results in the inability to produce eicosapentaenoic acid and docosahexaenoic acid, and has previously been associated with altered glucose and lipid metabolism. Skeletal muscle is a major site for insulin-stimulated glucose disposal; however, the consequences of reduced D6D activity on skeletal muscle metabolism are unknown.

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Fatty acid desaturase 2 (Fads2) encodes the delta-6 desaturase (D6D) enzyme, which is rate-limiting for the endogenous production of omega-3 long-chain polyunsaturated fatty acids (LC-PUFA). Numerous studies have reported the cardiometabolic health benefits of omega-3 LC-PUFA. Humans carrying genetic variants in the FADS2 gene have reduced levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), as well as oxylipins, in blood, erythrocytes and white adipose tissue (WAT).

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Dietary fatty acids are associated with the development of many chronic diseases, such as obesity, diabetes, cardiovascular disease, metabolic syndrome, and several cancers. This review explores the literature surrounding the combined and individual roles of n-6 PUFAs linoleic acid (LA) and arachidonic acid (AA) as they relate to immune and inflammatory response, cardiovascular health, liver health, and cancer. The evidence suggests that a pro-inflammatory view of LA and AA may be over simplified.

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Background: Recent genome-wide association studies in the Mexican population have identified several genetic loci associated with blood lipid levels in adults. However, studies focusing on the fatty acid desaturase (FADS) gene cluster have been understudied in this population, even though it seems associated with lipid profiles in other ethnicities. The aim of this study was to test associations between single nucleotide polymorphisms (SNPs) in the FADS cluster (rs174546, rs1535, rs174548, rs174550, rs174450, and rs174618) and serum lipid profiles in young Mexicans.

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This study focused on the effect of polyunsaturated fatty acids (PUFAs) during the lactation period of delta-6-desaturase knockout (D6D-KO) mice using an artificial rearing method. Newborn pups of D6D-KO male mice were separated from their dams within 48h and were fed artificial milk. Six formulations of milk were used: Control (Cont) milk (3.

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Dietary n-6 polyunsaturated fatty acids (PUFA) are widely perceived to promote inflammation and contribute to the development of chronic diseases. This dogma has been recently questioned due to evidence that n-6 PUFA, specifically linoleic acid (LA, 18:2n-6) and arachidonic acid (AA, 20:4n-6), do not appear to activate inflammatory signalling pathways when consumed in moderate amounts. However, delineating the independent roles of different dietary n-6 PUFA in vivo is challenging because LA is continuously converted into AA in a pathway regulated by the fatty acid desaturase 2 (Fads2) gene.

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The essentiality of arachidonic acid (ARA) and docosahexaenoic acid (DHA) for growth and brain function using delta-6-desaturase knockout (D6D-KO) mice and a novel artificial rearing method was investigated. Newborn male wild type (WT) and homozygous D6D-KO pups were separated from their dams within 48h and fed artificial milk containing α-linolenic acid and linoleic acid (Cont), or supplemented with ARA, DHA or both (ARA+DHA). After weaning, each group was fed diets similar to artificial milk in fatty acid composition for 7 weeks.

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In mammals, because they share a single synthetic pathway, n-6/n-3 ratios of dietary PUFAs impact tissue arachidonic acid (ARA) and DHA content. Likewise, SNPs in the human fatty acid desaturase (FADS) gene cluster impact tissue ARA and DHA. Here we tested the feasibility of using heterozygous Fads2-null-mice (HET) as an animal model of human FADS polymorphisms.

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We previously reported the importance of long-chain polyunsaturated fatty acid (LC-PUFA (>C20)) intake, including arachidonic acid (ARA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), for growth. This follow-up study focuses on ARA using a novel artificial rearing model during the lactation period in delta-6-desaturase knockout (D6D-KO) mice. Newborn D6D-KO male mouse pups were separated from dams within 48 hours and fed artificial milks containing 18-C essential fatty acids (EFAs) (16-17% LA, 3.

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Typically fatty acids (FA) exert differential immunomodulatory effects with n-3 [α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] and n-6 [linoleic acid (LA) and arachidonic acid (AA)] exerting anti- and pro-inflammatory effects, respectively. This over-simplified interpretation is confounded by a failure to account for conversion of the parent FA (LA and ALA) to longer-chain bioactive products (AA and EPA/DHA, respectively), thereby precluding discernment of the immunomodulatory potential of specific FA. Therefore, we utilized the Δ6-desaturase model, wherein knockout mice (D6KO) lack the Fads2 gene encoding for the rate-limiting enzyme that initiates FA metabolism, thereby providing a model to determine specific FA immunomodulatory effects.

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Consumers have difficulty using nutrition information. We hypothesized that graphically delivering information of select nutrients relative to a target would allow individuals to process information in time-constrained settings more effectively than numerical information. Objectives of the study were to determine the efficacy of the graphical method in (1) improving memory of nutrient information and (2) improving consumer purchasing behavior in a restaurant.

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In mammals, excess energy is stored primarily as triglycerides, which are mobilized when energy demands arise. This review mainly focuses on the role of long chain fatty acids (LCFAs) in regulating energy metabolism as ligands of peroxisome proliferator-activated receptors (PPARs). PPAR-alpha expressed primarily in liver is essential for metabolic adaptation to starvation by inducing genes for beta-oxidation and ketogenesis and by downregulating energy expenditure through fibroblast growth factor 21.

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Alpha-linolenic acid's (ALA) biological activity is poorly understood and primarily associated with its conversion to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Delta-6 desaturase (D6D) initiates the metabolism of linoleic acid (LA) and ALA to arachidonic acid, EPA, and DHA, respectively. In this study, D6D knock-out (D6KO) mice were used to evaluate the effects of ALA-rich oils in preventing hepatic steatosis and inflammation.

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Background: Polyunsaturated fatty acids (PUFA) have diverse biological effects, from promoting inflammation to preventing cancer and heart disease. Growing evidence suggests that individual PUFA may have independent effects in health and disease. The individual roles of the two essential PUFA, linoleic acid (LA) and α-linolenic acid (ALA), have been difficult to discern from the actions of their highly unsaturated fatty acid (HUFA) downstream metabolites.

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An omega-3 fatty acid, docosahexaenoic acid (DHA), is enriched in testicular membrane phospholipids, but its function is not well understood. The Fads2 gene encodes an enzyme required for the endogenous synthesis of DHA. Using Fads2-null mice (Fads2-/-), we found in our preceding studies that DHA deficiency caused the arrest of spermiogenesis and male infertility, both of which were reversed by dietary DHA.

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We have reported recently that enrichment of high-density lipoprotein (HDL) with phosphatidylcholine (PC) liposomes is effective in solubilizing cholesterol from isolated human atherosclerotic plaques. In the present study, we investigated the in vivo effect of enrichment of HDL with PC on regression of diet-induced atherosclerosis in rabbits. As part of the study, a preliminary in vitro study on blood collected from the cholesterol-fed rabbits was performed to assess the capacity of the HDL density (d > 1.

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