Weight Loss Composition and Metabolic Adaptation During Hypocaloric Dieting
The Relationship Between Weight Loss Composition, Body Composition Changes, and Metabolic Adaptation During a Hypocaloric Dietary Intervention
Weight loss induced by hypocaloric dietary interventions is commonly accompanied by reductions in resting metabolic rate (RMR), a phenomenon often described as metabolic adaptation. The magnitude of this decline varies substantially between individuals and may depend not only on the amount of weight lost but also on the composition of weight loss, particularly the relative contributions of fat mass and fat-free mass.
This prospective interventional study will investigate whether changes in body composition during a hypocaloric dietary intervention are associated with changes in RMR and metabolic adaptation. Approximately 150 adults with overweight or obesity will participate in a structured dietary program designed to induce moderate energy restriction. Body composition and resting metabolic rate will be assessed before and after the intervention to evaluate associations between fat mass loss, fat-free mass loss, and metabolic responses to weight reduction.
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Status
Condições
Intervenção / Tratamento
Descrição detalhada
Weight loss achieved through caloric restriction is consistently associated with reductions in resting metabolic rate (RMR). In many individuals, the decrease in energy expenditure exceeds what would be predicted from the loss of body mass or body composition alone, a phenomenon commonly described as metabolic adaptation or adaptive thermogenesis. This response has been proposed as one potential contributor to the difficulty many individuals experience in maintaining weight loss over time.
Fat-free mass is the primary determinant of resting energy expenditure because it includes metabolically active tissues such as skeletal muscle and organs. Consequently, the relative proportion of fat mass and fat-free mass lost during weight reduction may influence the magnitude of RMR decline. Dietary strategies that promote preservation of fat-free mass, such as adequate protein intake and engagement in physical activity, may attenuate metabolic slowing during weight loss. However, substantial inter-individual variability in metabolic responses to weight loss has been reported, and the role of weight-loss composition in shaping these responses remains incompletely understood.
The present study aims to examine the relationship between changes in body composition and changes in resting metabolic rate during a structured hypocaloric dietary intervention in adults with overweight or obesity. Participants will follow individualized dietary plans designed to produce a moderate energy deficit. Body composition will be assessed using dual-energy X-ray absorptiometry (DXA), and resting metabolic rate will be measured using indirect calorimetry at baseline and following completion of the intervention. Anthropometric measures and physical activity patterns will also be recorded.
By evaluating the relative contributions of fat mass loss and fat-free mass loss to changes in energy expenditure, this study aims to improve understanding of the physiological responses to weight reduction. The findings may help inform weight-loss strategies designed to minimize unfavorable metabolic adaptations and support more sustainable long-term weight management.
Tipo de estudo
Inscrição (Estimado)
Estágio
- Não aplicável
Contactos e Locais
Contato de estudo
- Nome: Yftach Prof. Gepner, PhD
- Número de telefone: +972 50-682-8501
- E-mail: gepner@tauex.tau.ac.il
Estude backup de contato
- Nome: Lien Bruck
- Número de telefone: +972 587487431
- E-mail: lienbruck@tauex.tau.ac.il
Critérios de participação
Critérios de elegibilidade
Idades elegíveis para estudo
- Adulto
- Adulto mais velho
Aceita Voluntários Saudáveis
Descrição
Inclusion Criteria
- Adults aged 18 years and older.
- Individuals living with overweight or obesity.
- Willingness and ability to comply with dietary recommendations and study procedures.
- Provision of written informed consent.
Exclusion Criteria
- Diagnosed metabolic or endocrine disorders known to affect energy expenditure.
- Use of medications known to substantially affect metabolism or body composition.
- Pregnancy or breastfeeding.
- Any medical condition that, in the opinion of the investigators, precludes safe participation.
Plano de estudo
Como o estudo é projetado?
Detalhes do projeto
- Finalidade Principal: Tratamento
- Alocação: N / D
- Modelo Intervencional: Atribuição de grupo único
- Mascaramento: Nenhum (rótulo aberto)
Armas e Intervenções
Grupo de Participantes / Braço |
Intervenção / Tratamento |
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Experimental: Hypocaloric Dietary Intervention
Participants will follow individualized hypocaloric dietary plans designed to produce a moderate daily energy deficit based on measured resting metabolic rate.
The intervention focuses on dietary energy restriction while supporting preservation of fat-free mass through adequate protein intake.
Body composition and resting metabolic rate will be assessed before and after the intervention to evaluate metabolic responses to weight loss.
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Participants will follow individualized dietary plans designed to produce an energy deficit of approximately 500-600 kcal/day relative to measured resting metabolic rate.
Protein intake will be prescribed at approximately 1.5 g/kg body weight per day to support preservation of fat-free mass.
Dietary plans will be adjusted as needed during the intervention period, and participants will attend regular follow-up visits to monitor progress and adherence.
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O que o estudo está medindo?
Medidas de resultados primários
Medida de resultado |
Descrição da medida |
Prazo |
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Change in Resting Metabolic Rate
Prazo: Baseline to end of dietary intervention (up to 12 months)
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Change in resting metabolic rate (RMR) measured by indirect calorimetry between baseline and post-intervention assessment.
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Baseline to end of dietary intervention (up to 12 months)
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Medidas de resultados secundários
Medida de resultado |
Descrição da medida |
Prazo |
|---|---|---|
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Change in Fat Mass
Prazo: Baseline to end of dietary intervention (up to 12 months)
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Change in total body fat mass measured using dual-energy X-ray absorptiometry (DXA).
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Baseline to end of dietary intervention (up to 12 months)
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Change in Fat-Free Mass
Prazo: Baseline to end of dietary intervention (up to 12 months)
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Change in total body fat-free mass measured using dual-energy X-ray absorptiometry (DXA).
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Baseline to end of dietary intervention (up to 12 months)
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Change in Body Weight
Prazo: Baseline to end of dietary intervention (up to 12 months)
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Change in body weight measured using a calibrated digital scale.
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Baseline to end of dietary intervention (up to 12 months)
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Change in Abdominal Circumference
Prazo: Baseline to end of dietary intervention (up to 12 months)
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Change in abdominal circumference measured using a standardized anthropometric tape at the midpoint between the lowest rib and iliac crest.
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Baseline to end of dietary intervention (up to 12 months)
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Intervention Duration
Prazo: Baseline to end of intervention (up to 12 months)
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Total duration of participation in the hypocaloric dietary intervention, recorded in weeks from baseline to intervention completion.
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Baseline to end of intervention (up to 12 months)
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Physical Activity Modality
Prazo: Baseline to end of dietary intervention (up to 12 months)
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Self-reported type of physical activity performed during the intervention, categorized as aerobic, resistance, combined, or none.
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Baseline to end of dietary intervention (up to 12 months)
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Colaboradores e Investigadores
Patrocinador
Investigadores
- Investigador principal: Yftach Gepner, PhD, Tel Aviv University
Datas de registro do estudo
Datas Principais do Estudo
Início do estudo (Estimado)
Conclusão Primária (Estimado)
Conclusão do estudo (Estimado)
Datas de inscrição no estudo
Enviado pela primeira vez
Enviado pela primeira vez que atendeu aos critérios de CQ
Primeira postagem (Real)
Atualizações de registro de estudo
Última Atualização Postada (Real)
Última atualização enviada que atendeu aos critérios de controle de qualidade
Última verificação
Mais Informações
Termos relacionados a este estudo
Palavras-chave
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Outros números de identificação do estudo
- 0012134-2
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