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Objective: To explore the experiences of female dietetic students strictly following 2 different isocaloric diets.

Design: A qualitative study as part of a randomized controlled feeding trial with a crossover design. Data were collected through individual interviews conducted 1–35 days after the intervention.

Setting: A university in Sweden.

Participants: Normal-weight, healthy female dietetic students (n = 17), aged 18–30 years, who completed the full intervention.

Intervention: Two 4-week diet periods with a washout period in between. Participants followed either a diet based on the Nordic Nutrition Recommendations or a ketogenic low-carb high-fat diet, consuming preprepared meals.

Phenomenon of Interest and Variables: Participants’ experiences of following the imposed diets.

Analysis: Data were analyzed using content analysis techniques, resulting in 1 main theme, 2 categories, and 5 subcategories.

Results: Participants reported challenges with loss of control over food choices, unexpected effects of diet restrictions, and social visibility. They also highlighted the importance of contributing to science and the benefits for their future careers.

Conclusions and Implications: First-hand experiences of strict diets provided valuable insights into the complexities of dietary adherence, enhancing empathy and competence in future dietetic practice. Integrating practical diet experiences into education could improve dietary counseling skills.

This work evaluated the protein quality of shiitake mushroom cultivated on low-nitrogen wood substrates that has previously been shown to enhance biorefinery processes through biological pretreatment. The effects of different initial mushroom substrates (IMSs) on amino acid (AA) content in shiitake fruit bodies (FBs) and spent mushroom substrates (SMSs) were studied using alder, birch and aspen wood substrates with varying nitrogen levels by adding whey (0-2%). Twenty-two AAs, including nine essential AAs (EAAs), were detected and analyzed. Total AA (TAA) content reached up to 13% in FBs and 5% in SMSs. The FBs showed good protein quality according to FAO/WHO guidelines, despite a low nitrogen content (∼0.6%) in IMS. Whey addition increased TAA and EAA levels in FBs while substrate species had distinct effects. Birch generally enhanced AA levels, alder reduced them, and aspen showed AA-specific but mostly positive responses. In SMS, whey addition also increased TAA, but the effects of wood species on TAA generally showed patterns opposite to that observed in FBs. Using 13 IMS chemical constituents as predictive variables in partial least squares regression, five models for AAs in FBs and 15 for SMS were achieved. The C/N ratio and soluble NO2 were major predictors, whereas Klason lignin had the least influence. The results suggested that shiitake SMS is a valuable resource for potential protein extraction and biofuel production.

This study investigates the effects of a ketogenic low-carbohydrate high-fat (LCHF) diet on body composition in healthy, young, normal-weight women. With the increasing interest in ketogenic diets for their various health benefits, this research aims to understand their impact on body composition, focusing on women who are often underrepresented in such studies. Conducting a randomized controlled feeding trial with a crossover design, this study compares a ketogenic LCHF diet to a Swedish National Food Agency (NFA)-recommended control diet over four weeks. Seventeen healthy, young, normal-weight women adhered strictly to the provided diets, with ketosis confirmed through blood β-hydroxybutyrate concentrations. Dual-energy X-ray absorptiometry (DXA) was utilized for precise body composition measurements. To avoid bias, all statistical analyses were performed blind. The findings reveal that the ketogenic LCHF diet led to a significant reduction in both lean mass (−1.45 kg 95% CI: [−1.90;−1.00]; p < 0.001) and fat mass (−0.66 kg 95% CI: [−1.00;−0.32]; p < 0.001) compared to the control diet, despite similar energy intake and physical activity levels. This study concludes that while the ketogenic LCHF diet is effective for weight loss, it disproportionately reduces lean mass over fat mass, suggesting the need for concurrent strength training to mitigate muscle loss in women following this diet.

Ketogenic low‐carbohydrate high‐fat (LCHF) diets are popular among young, healthy, normal‐weight individuals for various reasons. We aimed to investigate the effect of a ketogenic LCHF diet on low‐density lipoprotein (LDL) cholesterol (primary outcome), LDL cholesterol sub-fractions and conventional cardiovascular risk factors in the blood of healthy, young, and nor-mal‐weight women. The study was a randomized, controlled, feeding trial with crossover design. Twenty‐four women were assigned to a 4 week ketogenic LCHF diet (4% carbohydrates; 77% fat; 19% protein) followed by a 4 week National Food Agency recommended control diet (44% carbo-hydrates; 33% fat; 19% protein), or the reverse sequence due to the crossover design. Treatment periods were separated by a 15 week washout period. Seventeen women completed the study and treatment effects were evaluated using mixed models. The LCHF diet increased LDL cholesterol in every woman with a treatment effect of 1.82 mM (p < 0.001). In addition, Apolipoprotein B‐100 (ApoB), small, dense LDL cholesterol as well as large, buoyant LDL cholesterol increased (p < 0.001, p < 0.01, and p < 0.001, respectively). The data suggest that feeding healthy, young, normal‐weight women a ketogenic LCHF diet induces a deleterious blood lipid profile. The elevated LDL cholesterol should be a cause for concern in young, healthy, normal‐weight women following this kind of LCHF diet.

Ketogenic low-carbohydrate high-fat (LCHF) diets are increasingly popular in broad sections of the population. The main objective of this study was to evaluate the effects of a non-energy-restricted ketogenic LCHF diet on muscle fatigue in healthy, young, and normal-weight women. Twenty-four women were randomly allocated to a 4-week ketogenic LCHF diet followed by a 4-week control diet (a National Food Agency recommended diet), or the reverse sequence due to the crossover design. Treatment periods were separated by a 15 week washout period. Seventeen women completed the study and were included in the analyses. Treatment effects were evaluated using mixed models. The ketogenic LCHF diet had no effect on grip strength or time to fatigue, measured with handgrip test (day 24–26). However, cycling time to fatigue decreased with almost two minutes (−1.85 min 95% CI:[−2.30;−1.40]; p < 0.001) during incremental cycling (day 25–27), accommodated with higher ratings of perceived exertion using the Borg scale (p < 0.01). Participants’ own diary notes revealed experiences of muscle fatigue during daily life activities, as well as during exercise. We conclude that in young and healthy women, a ketogenic LCHF diet has an unfavorable effect on muscle fatigue and might affect perceived exertion during daily life activities.

OBJECTIVE: Abdominal fat accumulation after menopause is associated with low-grade inflammation and increased risk of metabolic disorders. Effective long-term lifestyle treatment is therefore needed.

METHODS: Seventy healthy postmenopausal women (age 60 ± 5.6 years) with BMI 32.5 ± 5.5 were randomized to a Paleolithic-type diet (PD) or a prudent control diet (CD) for 24 months. Blood samples and fat biopsies were collected at baseline, 6 months, and 24 months to analyze inflammation-related parameters.

RESULTS: Android fat decreased significantly more in the PD group (P = 0.009) during the first 6 months with weight maintenance at 24 months in both groups. Long-term significant effects (P < 0.001) on adipose gene expression were found for toll-like receptor 4 (decreased at 24 months) and macrophage migration inhibitory factor (increased at 24 months) in both groups. Serum interleukin 6 (IL-6) and tumor necrosis factor α levels were decreased at 24 months in both groups (P < 0.001) with a significant diet-by-time interaction for serum IL-6 (P = 0.022). High-sensitivity C-reactive protein was decreased in the PD group at 24 months (P = 0.001).

CONCLUSIONS: A reduction of abdominal obesity in postmenopausal women is linked to specific changes in inflammation-related adipose gene expression.

BACKGROUND: Excess body fat is a major health issue and a risk factor for the development of numerous chronic diseases. Low-carbohydrate diets like the Atkins Diet are popular for rapid weight loss, but the long-term consequences remain the subject of debate. The Scandinavian low-carbohydrate high-fat (LCHF) diet, which has been popular in Scandinavian countries for about a decade, has very low carbohydrate content (~5 E %) but is rich in fat and includes a high proportion of saturated fatty acids. Here we investigated the metabolic and physiological consequences of a diet with a macronutrient composition similar to the Scandinavian LCHF diet and its effects on the organs, tissues, and metabolism of weight stable mice.

METHODS: Female C57BL/6J mice were iso-energetically pair-fed for 4 weeks with standard chow or a LCHF diet. We measured body composition using echo MRI and the aerobic capacity before and after 2 and 4 weeks on diet. Cardiac function was assessed by echocardiography before and after 4 weeks on diet. The metabolic rate was measured by indirect calorimetry the fourth week of the diet. Mice were sacrificed after 4 weeks and the organ weight, triglyceride levels, and blood chemistry were analyzed, and the expression of key ketogenic, metabolic, hormonal, and inflammation genes were measured in the heart, liver, and adipose tissue depots of the mice using real-time PCR.

RESULTS: The increase in body weight of mice fed a LCHF diet was similar to that in controls. However, while control mice maintained their body composition throughout the study, LCHF mice gained fat mass at the expense of lean mass after 2 weeks. The LCHF diet increased cardiac triglyceride content, impaired cardiac function, and reduced aerobic capacity. It also induced pronounced alterations in gene expression and substrate metabolism, indicating a unique metabolic state.

CONCLUSIONS: Pair-fed mice eating LCHF increased their percentage of body fat at the expense of lean mass already after 2 weeks, and after 4 weeks the function of the heart deteriorated. These findings highlight the urgent need to investigate the effects of a LCHF diet on health parameters in humans.

Introduction: Muscle sample collection can introduce variation in any measured variable due to inter- and intramuscle variation. We investigated the variation in gene expression and fiber type composition after repeated biopsy sampling from the vastus lateralis muscle. Methods: Six subjects donated 3 tissue samples each. One hour after baseline sampling from 1 vastus lateralis muscle, samples from both vastus lateralis muscles were obtained. Results: The fiber type composition differed between biopsies taken from the same leg. There were no within-subject differences in gene expression between the 3 biopsies. Multivariate analysis supports a model in which gene expression differs significantly between individuals but is not affected by repeated muscle biopsy sampling from the same subject. Conclusion: One vastus lateralis muscle sample per subject is sufficient to establish a reliable baseline for comparing gene expression representing selected pathways over time within the same individual.