Condition category
Nutritional, Metabolic, Endocrine
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
An intermittent energy restriction (IER) approach to weight loss is easier for some people to follow as it involves short spells of severe energy restriction alternated with days of usual energy intake. However, there is currently not enough evidence regarding the potential effectiveness and benefits of IER compared with other food-based weight loss methods. We aim to compare the effectiveness of IER with continuous energy restriction (CER) on weight loss, blood glucose levels and markers of CVD risk in a selected group of NHS Rotherham Institute of Obesity (RIO) weight loss patients.

Who can participate?
Obese male and female patients, aged 18-65, attending a weight loss programme at the Rotherham Institute of Obesity are eligible to participate in this study.

What does the study involve?
The study will involve participating in a six-month weight loss programme. Participants will be randomly allocated to either the IER or the CER programme. The IER programme will be given in the form of the LighterLife Fast plan, which advocates 5 days unrestricted healthy eating and 2 days fasting, which consists of 4 fast LighterLife Foodpacks providing about 600 kcal each day. This will be compared with the CER programme, whereby patients will be instructed to consume a healthy diet with a daily deficit of about 500 kcal. Weight loss, changes in waist circumference as well as changes in blood glucose, fasting glucose and insulin, full lipids and inflammatory markers will be assessed. We will also assess changes in blood flow and blood pressure as well as dietary adherence using food diaries.

What are the possible benefits and risks of participating?
Patients will lose weight and may see improvements in other diseases associated with being obese. The study will contribute to a greater understanding and depth of knowledge about how well the different weight loss methods work and may provide the patient with a more acceptable way to lose and manage their weight. There are no foreseen disadvantages or risks of taking part.

Where is the study run from?
Rotherham Institute of Obesity, Rotherham, UK.

When is the study starting and how long is it expected to run for?
The study is expected to start in early February 2014 and will run for 6 months.

Who is funding the study?
Lighterlife UK Ltd, UK.

Who is the main contact?
Dr Kelly Johnston
01279 636998

Trial website

Contact information



Primary contact

Dr Matthew Capehorn


Contact details

Rotherham Institute for Obesity (RIO)
Clifton Medical Centre
The Health Village
Doncaster Gate
S65 1DA
United Kingdom
+44 (0)844 477 3622

Additional identifiers

EudraCT number number

Protocol/serial number

Rotherham Institute for Obesity (RIO)/Lighterlife Fast

Study information

Scientific title

The comparative effects of continuous versus intermittent energy restriction (CER and IER respectively) on changes in weight, anthropometry and other cardio-metabolic disease risk markers in a selected cohort of RIO weight loss patients


Study hypothesis

The aim of this study is to compare the feasibility and efficacy of IER with CER on a range of outcomes measures including weight loss & anthropometry, measures of glycaemic control and appetite, and other biochemical markers of CVD risk..

Ethics approval

South Yorkshire NHS Ethics Committee, ref: 14-YH-0018

Study design

Randomised non-blinded single-centre study

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Weight loss in obese individuals


Randomised comparison using 200 overweight or obese, male and female participants (100 randomised to each group).

The IER leg of this study will be delivered in the form of the Lighterlife Fast 5:2 diet, which advocates 5 days healthy eating (consuming energy levels commensurate with weight maintenance) and 2 days fasting, which advises consumption of 4 fast Lighterlife Fast foodpacks providing 600 kcal on those two days. This will be compared with the CER leg of the study, whereby patients will be instructed to consume a healthy diet with a daily deficit of approximately 500 kcal.

The total duration of the intervention is 26 weeks. Participants on this trial remain patients of RIO and as such will be followed up regularly thereafter, but data will not be collected for this study.

Updated 16/04/2014:
Participants return at 12 months for the following measurements:
1. Weight
2. Height
3. BMI
4. Waist circumference
5. Hip circumference
6. Chest circumference
7. Blood pressure
8. Bio-impedance
9. Report on co-morbidities
10. Current medication

Intervention type



Not Applicable

Drug names

Primary outcome measure

1. Weight
2. Waist circumference

Secondary outcome measures

1. Fasting glucose, lipids and insulin
2. Liver function tests (LFTs), thyroid function tests (TFTs), Hba1c, adiponectin, leptin, C-reactive protein and IGF-1
3. Bio-impedance and blood pressure as well as dietary adherence using validated food diaries

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Healthy males and females, aged 18-65
2. Body mass index (BMI) > 30

Participant type


Age group




Target number of participants


Total final enrolment


Participant exclusion criteria

Those who are pregnant or breastfeeding

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Rotherham Institute for Obesity (RIO)
S65 1DA
United Kingdom

Sponsor information


Lighterlife UK Ltd (UK)

Sponsor details

Cavendish House
Harlow Business Park
CM19 5QF
United Kingdom
+44 (0)127 963 6955

Sponsor type




Funder type


Funder name

Lighterlife (UK)

Alternative name(s)

Funding Body Type

private sector organisation

Funding Body Subtype

For-profit companies (industry)


United Kingdom

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

2019 results in: (added 14/10/2019)

Publication citations

Additional files

Editorial Notes

14/10/2019: The following changes were made to the trial record: 1. Publication reference added. 2. The total final enrolment was added. 07/03/2017: No publications found in PubMed, verifying study status with principal investigator