Rationale and Protocol for a Randomized Controlled Trial Comparing Fast versus Slow Weight Loss in Postmenopausal Women with Obesity—The TEMPO Diet Trial

Abstract

Very low energy diets (VLEDs), commonly achieved by replacing all food with meal replacement products and which result in fast weight loss, are the most effective dietary obesity treatment available. VLEDs are also cheaper to administer than conventional, food-based diets, which result in slow weight loss. Despite being effective and affordable, these diets are underutilized by healthcare professionals, possibly due to concerns about potential adverse effects on body composition and eating disorder behaviors. This paper describes the rationale and detailed protocol for the TEMPO Diet Trial (Type of Energy Manipulation for Promoting optimal metabolic health and body composition in Obesity), in a randomized controlled trial comparing the long-term (3-year) effects of fast versus slow weight loss. One hundred and one post-menopausal women aged 45–65 years with a body mass index of 30–40 kg/m2 were randomized to either: (1) 16 weeks of fast weight loss, achieved by a total meal replacement diet, followed by slow weight loss (as for the SLOW intervention) for the remaining time up until 52 weeks (“FAST” intervention), or (2) 52 weeks of slow weight loss, achieved by a conventional, food-based diet (“SLOW” intervention). Parameters of body composition, cardiometabolic health, eating disorder behaviors and psychology, and adaptive responses to energy restriction were measured throughout the 3-year trial.

Effect of Weight Loss via Severe vs Moderate Energy Restriction on Lean Mass and Body Composition Among Postmenopausal Women With Obesity

“…The full inclusion and exclusion criteria and our rationale for these have been detailed in our published protocol. 27 The trial was conducted in accordance with the Declaration of Helsinki 28 and Good Clinical Practice guidelines. 29 All participants provided written informed consent prior to participation.…”

Less Binge Eating and Loss of Control over Eating Are Associated with Greater Levels of Mindfulness: Identifying Patterns in Postmenopausal Women with Obesity

“…Participants were enrolled in the TEMPO Diet Trial ( T ype of E nergy M anipulation for P romoting optimum metabolic health and body composition in O besity, Australian New Zealand Clinical Trials Registry Number 12612000651886), a randomized controlled trial investigating the effects of weight loss via severe versus moderate dietary energy restriction on a range of physiological and psychological variables. Participant eligibility was described in full elsewhere [26]. In brief, eligible participants were ambulatory, sedentary (<60 min of physical activity per week), and had been weight stable for at least six months (±2 kg).…”

“…Participants completed a total of four questionnaires for this study: two questionnaires measuring eating disorder behaviors (the Eating Disorder Examination Questionnaire, EDE-Q, and the Loss of Control over Eating Scale, LOCES) and two questionnaires assessing mindfulness (the Five-Facet Mindfulness Questionnaire, FFMQ, and the Langer Mindfulness Scale, LMS). These questionnaires were administered two weeks prior to commencement of the intervention during a face-to-face appointment at our clinical research facility (for more details, refer to our previous publication [26]). Data from the LOCES were only available for 88 participants, as we started administering this scale after data collection had begun.…”

“…The EDE-Q, a modified 28-item version of the original Eating Disorder Examination, is a commonly used self-report questionnaire assessing eating disorder symptomology that displays high test–retest reliability and internal consistency [27]. Some minor modifications were made to the original EDE-Q to reflect the characteristics of the current sample, which are described in full elsewhere [26]. A noteworthy change was the addition of a question derived from a previous study [28] designed to capture subjective binge eating episodes: “Have you had other episodes of eating in which you have had a sense of having lost control and eaten more than you would like, but have not eaten a very large amount of food given the situation?…”

Urine dipsticks are not accurate for detecting mild ketosis during a severely energy restricted diet

“…Details of the study protocol and 12-month intervention for the severely energy-restricted arm of the TEMPO Diet Trial have been reported in detail previously. [23][24][25] Briefly, participants were randomized to 4 months (16 weeks) of severe energy restriction of 65% to 75% relative to estimated energy expenditure, using a total meal replacement diet, followed by moderate energy restriction of 35% to 25% for an additional 8 months (36 weeks). The total meal replacement products used in the severely energy-restricted diet provided between 2,630 (630 kcal) and 3,260 kJ (780 kcal) per day in this group of participants.…”