Sensory Responses to Fat are Not Affected by Varying Dietary Energy Intake From Fat and Saturated Fat Over Ranges Common in the American Diet

Objective To examine the effects of manipulating dietary fat in foods on sensitivity and hedonic response to fat in selected foods.Design Twenty subjects were randomly assigned to a sequence of three 8-week experimental diets (average American diet, step 1 diet, low-saturated-fat diet) that varied in energy from fat (37%, 30%, and 26%, respectively) and saturated fat (17%, 10%, and 6%, respectively). Subjects participated in sensory tests designed to assess their sensitivity to and liking for fat in several foods, before the study (baseline), after consumption of each diet, and after the study (washout).Subjects/setting Subjects were participants in the Dietary Effects on Lipoprotein and Thrombogenic Activity (DELTA) study.Results No significant differences were found among diets for difference thresholds (ie, just noticeable differences) for fat in milk and pudding, ad libitum mixing of low- and high-fat samples of milk and soup, and hedonic scaling of fat concentrations in milk and muffins and of cheese, mayonnaise, hot dog, and pastry samples.Applications/conclusions Within the dietary fat ranges and for the fat stimuli tested in this study, dietary fat as percentage of energy from fat and saturated fat was not a significant determinant of sensitivity to and/or liking for fat. Sensory factors should not be a barrier to the implementation of low-fat diets such as the step 1 and low-saturated-fat diets. J Am Diet Assoc. 1999;99:690–696.     

Evaluation of the Measurement Properties of Four Performance Outcome Measures in Patients with Elective Hip Replacements,Elective Knee Replacements,or Hip Fractures

Objectives

To evaluate the measurement properties of four performance outcome (PerfO) measures (timed up and go, four-step stair climb, long stair climb, and repeated chair stand) in three patient populations(elective total hip replacement [eTHR], elective total knee replacement [eTKR], and hip fracture [HF]).

Saturation of Dietary Fats and Liver and Serum Lipids

Thirteen edible fats were fed to rats during a post-weaning period of seven weeks. Liver and serum cholesterol values were determined as well as the distribution of unsaturated fatty acids in cholesterol esters.     

Nutrition Recommendations Update: Dietary Fats and Children

This is a report of the Joint Working Group of the Canadian Paediatric Society and Health Canada.* Published with permission from the Health Protection Branch, Health Canada.     

The New Dietary Fats in Health and Disease

Lipids are an integral part of the routine diet of patients and the general public. In this article, the physiologic properties of various dietary lipids are reviewed, beginning with those most commonly consumed—the long-chain triglycerides (LCTs) and extending to those with special purposes: the short- and medium-chain triglycerides. The nutritional dietary management of patients typically includes physical mixtures of lipids. Recently, structured triglycerides (STs), which combine advantages from conventional fats with those of special purposes, have become available. STs are currently developed by interesterifying a mixture of conventional fats and oils, usually with medium-chain triglycerides, to achieve a specific fatty acid profile. This results in a triglyceride containing combinations of short-, medium-, and long-chain fatty acids on a single glycerol backbone. They have unique chemical, physical, or physiologic properties that are not observed by simply blending mixtures of the starting fats and oils. A number of STs are under intense laboratory and clinical investigation in models of cancer, burns, and immune dysfunction. Much interest in the fatty acids resides in the sn-2 position on the glycerol molecule. This is because the fatty acid in the sn-2 position of triglycerides is preferentially absorbed as the 2-monoglyceride and serves as the template for reesterification by intestinal cells to re-form triglycerides. The sn-2 fatty acids are also preferentially preserved as components of chylomicrons and very-low-density lipoprotein particles for ultimate incorporation in tissue membranes. Technology is evolving to create STs with a selected fatty acid in this sn-2 position. For instance, incorporating linoleic, arachidonic, or eicosapentaenoic acid at the sn-2 position is being evaluated for the specific objective of modulating serum cholesterol concentrations and essential fatty acid absorption (a review of this work is included). J Am Diet Assoc. 1997;97:280–286.     

Further Studies of Cholesterol, Fats and Fatty Acids

Varying levels of saturated and unsaturated fats, protein and cholesterol influenced the chemical composition of chicken aortas. Surprisingly, unsaturated fats as well as wheat germ increased serum cholesterol deposition in rabbits.     

Free and Esterified Sterol Composition of Edible Oils and Fats

The free and esterified sterol concentrations in 31 edible oils and fats were determined, including individual values for sitosterol, campesterol, stigmasterol, brassicasterol, Δ⁵-avenasterol, sitostanol, campestanol, and cholesterol. Free and esterified sterols were separated by solid-phase extraction (SPE), saponified, and quantified as trimethylsilyl ether derivatives using capillary gas–liquid chromatography. Considerable variability in the proportion of free and esterified sterols was observed among different oils and fats, with free sterols ranging from 32 to 94% of total sterols. Refining or hydrogenation tended to decrease total sterols and increase esterified sterols. Differences in total phytosterol content and the proportion of free and esterified sterols also were evident for different samples of some oils. Among four soybean oils, total phytosterols ranged from 205 to 287 mg/100 g, and free sterols constituted 68–81% of total sterols; two different shortenings differed 62% in total sterol content (185–301 mg/100 g). Such variability in phytosterol composition likely reflects differences in processing, growing season, or variety of a particular plant source.     

Healthcare Utilization and Costs of Knee or Hip Replacements versus Pain-Relief Injections

Background

Given the dramatic increase in total knee and hip replacement procedures among the US population aged 45 years and older, there is a need to compare the downstream healthcare utilization and costs between patients who undergo joint replacement and those who receive intraarticular injections as a low-cost alternative.

Objective

To compare changes in osteoarthritis (OA)-related healthcare utilization and costs for Medicare members with OA who underwent knee or hip replacement versus those receiving steroid or viscosupplementation injections.

Methods

Medicare members aged ≥45 years diagnosed with OA were identified for this retrospective longitudinal study. Data were compared for patients who underwent primary knee or hip replacement surgery between July 1, 2007, and June 30, 2012, and those receiving injection of pain-relief medication during the same period. The date of joint replacement surgery was considered the index date. For the comparison cohort, the index date was 180 days postinjection of the first intraarticular injection. Medical and pharmacy claims were examined longitudinally in 90-day increments, from 180 days preindex until 360 days postindex. Difference-in-difference analyses were conducted to compare the change in OA-related healthcare costs, postindex versus preindex, between the study cohorts. Time-to-event analyses were used to measure rates of readmissions and venous thromboembolism (VTE).

Results

The mean age was 70.7 years for patients with knee replacement, 71.7 years for those with hip replacement, and 71.1 years for those receiving pain-relief injection (P <.0001). The RxRisk-V comorbidity index scores were 4.7, 4.4, and 4.8, respectively (P <.0001). Difference-in-difference analyses indicated that decreases in OA-related costs were greater for the joint replacement cohorts (coefficient for knee replacement*time: −0.603; hip replacement*time: −0.438; P <.001 for both) than for the comparison cohort. The VTE rates were 5.6% (knee) and 5.1% (hip) postsurgery versus 1.4% (knee) and 1.3% (hip) presurgery.

Conclusion

The overall difference-in-difference results showed a greater decrease in healthcare utilization and costs for the members with joint replacement than for those receiving injection.     

Challenges of Utilizing Healthy Fats in Foods

Over the past few decades, the Dietary Guidelines for Americans has consistently recommended that consumers decrease consumption of saturated fatty acids due to the correlation of saturated fatty acid intake with coronary artery disease. This recommendation has not been easy to achieve because saturated fatty acids play an important role in the quality, shelf life, and acceptability of foods. This is because solid fats are critical to producing desirable textures (e.g., creaminess, lubrication, and melt-away properties) and are important in the structure of foods such as frozen desserts, baked goods, and confectionary products. In addition, replacement of saturated fats with unsaturated fats is limited by their susceptibility to oxidative rancidity, which decreases product shelf life, causes destruction of vitamins, and forms potentially toxic compounds. This article will discuss the fundamental chemical and physical properties in fats and how these properties affect food texture, structure, flavor, and susceptibility to degradation. The current sources of solid fats will be reviewed and potential replacements for solid fats will be discussed.