Popular fad diets: An evidence-based perspective

Undergraduates' knowledge, attitudes, and behaviours associated with fad diets

PURPOSE

We aimed to determine undergraduate students' use and knowledge of fad diets as well as examine how appealing students found these diets given the goal of rapid weight loss and/or improved health. Twenty-three students from a Midwestern university (mean age = 19.2, mean BMI = 27.35, 69.6% female) were recruited through new student orientations for this qualitative study. Approximately 52% of participants identified as White, 30% as Black, 13% as Asian, and 4% as multi-racial.

METHODS

Knowledge and opinions about fad diets were collected via focus groups and individual interviews. Coding of transcripts was conducted by hand using the constant comparative method and data were analysed based on grounded theory.

RESULTS

Two primary themes emerged: very negative views of fad diets and the importance of healthy eating. Although few participants had tried fad diets, they thought these diets: 1) did not lead to sustained weight loss, 2) were associated with disappointment and health issues, and 3) were money-making schemes delivered heavily through social media. Participants also valued healthy eating.

CONCLUSION

Experimental studies are needed to examine how healthy eating among university students can be supported through credible sources, accurate information, and established connections via innovative social media platforms.

A qualitative analysis of college women's experiences with dieting

OBJECTIVE

Dieting is a known risk factor for disordered eating, yet many college women engage in this behavior. Given the popularity of diets, and the risks associated with dieting, it is important to enhance understanding of dieters' experiences. This study utilized a qualitative approach to investigate college women's experiences of dieting.

PARTICIPANTS

Eighty-four woman-identifying undergraduates [42% White, 24% Asian, 20% Black, 14% other; Mage = 19.18 (1.77)] who endorsed dieting were included in the study.

METHODS

Participants provided short-answer responses to open-ended questions. Data were analyzed using a thematic analysis approach.

RESULTS

The following themes were identified: A complicated relationship, variability of experiences, and social factors. Subthemes highlighted the complexity of college women's dieting behavior.

CONCLUSIONS

Results provide important insight into college women's dieting experiences and their consequences. Future qualitative research should aim to understand how to apply these findings to eating disorder prevention efforts.

The Potential Effects of the Ketogenic Diet in the Prevention and Co-Treatment of Stress, Anxiety, Depression, Schizophrenia, and Bipolar Disorder: From the Basic Research to the Clinical Practice

BACKGROUND

The ketogenic diet (KD) has been highly developed in the past for the treatment of epileptic pathological states in children and adults. Recently, the current re-emergence in its popularity mainly focuses on the therapy of cardiometabolic diseases. The KD can also have anti-inflammatory and neuroprotective activities which may be applied to the prevention and/or co-treatment of a diverse range of psychiatric disorders.

PURPOSE

This is a comprehensive literature review that intends to critically collect and scrutinize the pre-existing research basis and clinical data of the potential advantageous impacts of a KD on stress, anxiety, depression, schizophrenia and bipolar disorder.

METHODS

This literature review was performed to thoroughly represent the existing research in this topic, as well as to find gaps in the international scientific community. In this aspect, we carefully investigated the ultimate scientific web databases, e.g., PubMed, Scopus, and Web of Science, to derive the currently available animal and clinical human surveys by using efficient and representative keywords.

RESULTS

Just in recent years, an increasing amount of animal and clinical human surveys have focused on investigating the possible impacts of the KD in the prevention and co-treatment of depression, anxiety, stress, schizophrenia, and bipolar disorder. Pre-existing basic research with animal studies has consistently demonstrated promising results of the KD, showing a propensity to ameliorate symptoms of depression, anxiety, stress, schizophrenia, and bipolar disorder. However, the translation of these findings to clinical settings presents a more complex issue. The majority of the currently available clinical surveys seem to be moderate, usually not controlled, and have mainly assessed the short-term effects of a KD. In addition, some clinical surveys appear to be characterized by enormous dropout rates and significant absence of compliance measurement, as well as an elevated amount of heterogeneity in their methodological design.

CONCLUSIONS

Although the currently available evidence seems promising, it is highly recommended to accomplish larger, long-term, randomized, double-blind, controlled clinical trials with a prospective design, in order to derive conclusive results as to whether KD could act as a potential preventative factor or even a co-treatment agent against stress, anxiety, depression, schizophrenia, and bipolar disorder. Basic research with animal studies is also recommended to examine the molecular mechanisms of KD against the above psychiatric diseases.

Efficacy and safety of prolonged water fasting: a narrative review of human trials

The goal of this narrative review is to summarize the effects of prolonged fasting on various metabolic health measures, including body weight, blood pressure, plasma lipids, and glycemic control. Prolonged fasting is characterized by consciously eating little to no food or caloric beverages for several days to weeks. Results reveal that prolonged fasting for 5-20 days produces potent increases in circulating ketones, and mild to moderate weight loss of 2-10%. Approximately two-thirds of the weight lost is lean mass, and one-third is fat mass. The excessive lean mass loss suggests that prolonged fasting may increase the breakdown of muscle proteins, which is a concern. Systolic and diastolic blood pressure consistently decreased with prolonged fasting. However, the impact of these protocols on plasma lipids is less clear. While some trials demonstrate decreases in LDL cholesterol and triglycerides, others show no benefit. With regard to glycemic control, reductions in fasting glucose, fasting insulin, insulin resistance, and glycated hemoglobin (HbA1c) were noted in adults with normoglycemia. In contrast, these glucoregulatory factors remained unchanged in patients with type 1 or type 2 diabetes. The effects of refeeding were also examined in a few trials. It was shown that 3-4 months after the fast was completed, all metabolic benefits were no longer observed, even when weight loss was maintained. With regard to adverse events, metabolic acidosis, headaches, insomnia, and hunger were observed in some studies. In summary, prolonged fasting appears to be a moderately safe diet therapy that can produce clinically significant weight loss (>5%) over a few days or weeks. However, the ability of these protocols to produce sustained improvements in metabolic markers warrants further investigation.

The Human Interference Scoring System (HISS): A New Tool for Quantifying Food Quality Based on Its Level of Processing

The Human Interference Scoring System (HISS) is a novel food-based diet-quality-classification system based on the existing NOVA method. HISS involves food and fluid allocation into categories from digital imagery based on food processing levels, followed by meal plan analysis using food-servings quantification. The primary purpose of this work was to evaluate the reliability of HISS. Trained nutrition professionals analyzed digital photographs from five hypothetical 24 h food recalls and categorized foods into one of four HISS categories. A secondary purpose was to assess the nutrient composition of the food recalls and other selected foods from the HISS categories. Participants effectively categorized foods into HISS categories, with only minor discrepancies noted. High inter-rater reliability was observed in the outer HISS categories: unprocessed and ultra-processed foods. Ultra-processed items consistently displayed elevated energy, carbohydrates, and sugar compared to unprocessed foods, while unprocessed foods exhibited notably higher dietary fiber. This study introduces the HISS as a potentially useful tool for quantifying a food-quality-based system using digital-photography-based assessments. Its high inter-rater reliability and ability to capture relationships between food processing levels and nutrient composition make it a promising method for assessing dietary habits and food quality.