LIMITFOOD2 is a randomized clinical intervention study that investigates the effects of two different intermittent fasting protocols compared to a control group on the health of obese adults. A total of 90 participants will be randomized into three equally sized groups: a modified alternate day fasting, a time-restricted eating and a control group, receiving general weight-loss counseling.
The prevalence of overweight and obesity worldwide has risen considerably in the past century with more than one billion overweight persons, and about 600 million obese patients in 2015. Humans in modern societies typically eat at least three main meals per day and snacks around the clock. This change in eating pattern in terms of quantity and frequency leads to overconsumption of food and consequently to excess weight. Furthermore, obesity increases the risk of developing diabetes, cardiovascular disease and several types of cancer. The world health organization (WHO) has stated that there are 2.8 million deaths per year as a result of overweight and obesity. In recent years, the concept of re-introduced fasting intervals in the form of intermittent fasting (IF) protocols became a popular alternative dietary strategy with the aim to achieve weight control and improve metabolic health. There are several different IF protocols, the most popular is time-restricted eating (TRE), which allows ad libitum (at one's pleasure) energy intake within a defined time period each time (6 to 12 hours). Another IF protocol is alternate day fasting (ADF), on 'feast days' one can consume food ad libitum, while on 'fast days' no or little food is consumed, feast and fast days alternate throughout the week. Animal studies and previous human clinical trials have provided evidence that various types of IF lead to weight loss and improved health markers. So far, interventional studies focused on the comparison of IF versus a control group, however only few studies compared different IF protocols directly. Given both the evidence for beneficial effects of IF as well as its growing popularity, it seems mandatory to reveal possible differences in the effectiveness of different protocols. The present project will allow to directly compare two types of IF with each other and with a control group in obese participants. Furthermore, established and novel monitoring tools to track individual progress during IF are scarcely used so far but may become an important help in the future and thus, will be implemented in this trial.
Study Type
INTERVENTIONAL
Allocation
Participants are instructed to fast every other day.
Participants are instructed to limit food intake to two main meals consumed in maximum 8 hours per day
Participants will receive nutrition counseling to structure their main meals according to the plate model for weight-loss and to reduce number of consumed plates.
Department of Endocrinology, Diabetology and Clinical Nutrition
Zurich, Canton of Zurich, Switzerland
RECRUITINGFat Volume
Change in body fat volume measured with MRI
Time frame: 8 weeks
Distribution of fat volume
Changes in subcutaneous and visceral fat volume measured with MRI
Time frame: 8 weeks
Concentration of Leptin
Change in leptin concentrations will be measured.
Time frame: 8 weeks
Changes in Insulin Sensitivity
Insulin Sensitivity will be assessed using the homeostasis model assessment of insulin resistance (HOMA-IR), which is calculated from insulin and glucose concentration from a 12 hours fasting blood sample.
Time frame: 8 weeks
Changes in Fasting Lipids
Changes in concentration of Apolipoprotein B and triglycerides will be measured from a 12 hours fasting blood sample.
Time frame: 8 weeks
Changes in Inflammatory Markers
Changes in concentration of C-reactive protein and Interleukin-1beta will be measured.
Time frame: 8 weeks
Free triiodothyronine (fT3)
Change in serum levels of fT3 will be measured.
Time frame: 8 weeks
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RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
90