top of page
Healthy Food


The WHY of The APPLE Study?

There are only two approved dietary recommendations for individuals with psoriasis by the Medical Board of the National Psoriasis Foundation. Currently, the recommendations are low calorie diets, in patients with psoriasis who are overweight and a gluten-free diet, in patients who are gluten-sensitive. There is emerging evidence suggesting the potential beneficial effects of other dietary patterns. Amongst these patterns are the ketogenic diet, intermittent fasting as well as Mediterranean dietary patterns; none of which have received an approved dietary recommendation for psoriasis.

To provide evidence-based recommendations, it is of critical importance to first understand the current diet and life-style patterns in a population with psoriasis. By capturing the current diet and life-style patterns, we strive to understand if there are certain foods and habits that are more commonly found in people with more severe psoriasis compared with those with milder forms of psoriasis.

This study is unique in its kind as it would be the first national study providing a comprehensive view of the diet and lifestyle patterns of people living with psoriasis. The insights from this study will determine the study design of a clinical trial: the second component of to the Diet and Psoriasis Project. The clinical trial will directly assess the impact of dietary interventions on psoriasis severity in a patient population. 

Fresh Produce


Can I take part? 

To participate in The APPLE Study:

  • You must be 18 years or older

  • You have been medically diagnosed with psoriasis

  • You are a resident in the United Kingdom

  • You are able to complete surveys in English 

Do I have to take part? 

  • Participation is completely voluntary 

  • You should only take part if you want to

  • Choosing not to take part will not disadvantage you in any way 

  • If you choose to participate, you will be asked to provide your consent  

  • We encourage you to contact the research team through the Contact page, if you have any questions about participating

How do I enrol in The APPLE Study? 

  • You will first be asked to read an information sheet

  • You will then be asked to provide informed consent

  • Once informed consent has been obtained you will be directed to a short multiple-choice screening questionnaire (4 questions)

  • If you are eligible to participate, you will be directed to start The APPLE Study 


How do I provide informed consent?

To provide informed consent, you will need to indicate (by checking the boxes), that you have read and understood the information provided and that you consent to your data being used for the purposes explained.​

How do I take part in The APPLE Study?

Click the "Start the APPLE study survey" button on the home page.

Where does participation take place?

  • Participation in The APPLE Study is entirely online

  • You will need an internet connection to access the online survey and diet diary

What do I need to do to successfully complete The APPLE Study?

You will need to complete:

  • The APPLE Study survey; this is a multiple-choice survey.

  • The APPLE Study Intake24; this is the series of diet diaries.


What device should I use to complete the survey and diet diary?

  • laptop

  • desktop computer

*Questions will not display correctly on a smartphone*

What does The APPLE Study survey look like?

It is a multiple choice survey.


  • Stage 1 asks questions about your demographics, general health, sleep, life-style patterns, and physical activity.

  • Stage 2 asks questions about your psoriasis.

  • Stage 3 asks questions about your dietary intake.  


Stage 1-3 of the survey takes 30-40 minutes to complete.

How do I complete the survey?

  • You are welcome to complete the survey at a time and place that is most suitable for you.

  • Once you start the survey, your responses will be autosaved as you progress.

What happens if I close my browser window?

If you close your browser window and return to that same link, on the same browser and on the same device.

*You will be able to resume where you left off, provided you haven't deleted browsing history and/or cookie/data*


Once I start, how long do I have to complete the survey?

The progress of the survey will be saved for up to one week. After one week your responses will be recorded and and will be considered incomplete. Incomplete responses will still be included in the final data analysis.

What is The APPLE Study Intake24?

It is a diet diary asking you to complete a series of  24-hour diet recalls.

  • A 24-hour diet recall will ask you to record all of the food and drink (and their quantities) that you consumed the day before (between midnight and midnight).

  • There are built in tools to estimate quantities so you will not need to weigh your food!  

Stage 4 of The APPLE Study takes 20-30 minutes per diet recall.

Where can I find my unique diet diary link?

Your unique diet diary link will be emailed to you. It will be sent to the same email account used to enrol in The APPLE Study.


How long will it take to receive the unique diet diary link?

You should receive an email containing the unique diet diary link within 24-48H from completing the survey.

Who is the sender of the email containing the unique diet diary link?

Its been 24-48H and I can't find the email containing my unique diet diary link?


What do I do when I receive the email with my unique diet diary link?

  • Open the email 

  • Click on the unique diet diary link

  • You will be instantly directed to your personal profile to submit your 24-hour diet recalls


How do I complete The APPLE Study Intake24?

  • You will need to complete a total of 4 24-hour diet recalls:

    • 3 of the 24-hour diet recalls should be completed on 3 weekdays

    • 1 of the 24-hour diet recalls should be completed on 1 weekend day  

  • You will be allowed to complete one 24-hour diet recall per day

  • This means you will need to complete the 24-hour diet recalls on individual days

  • Your progress will be auto saved as you complete the recalls day to day


Do I need to complete the 24-hour diet recalls on consecutive days?

The 24-hour diet recalls do not need to be completed on consecutive days. 

Are instructions provided to complete the 24-hour diet recalls?

  • Before starting the 24-hour diet recalls, there is a short 8 minute instructional video.

  • Built in guidance/prompts are provided throughout the logging of your 24-hour diet recalls.


How do I access my diet diary on the following days?

  • Open the email sent to you by dietandpsoriasisprject@kcl.acuk

  • Click on the unique diet diary link

  • It will automatically open your profile to the recall due on that day


I logged my first diet diary, why can I not access my second diet diary?

You will need to leave exactly 24 hours between your diet diaries. Diet diaries are representative of 24-hour dietary recalls, and there are 24 hours between the entries.

If you start your first diet diary at 08:00 AM, your next diet diary will become available at 08:00 AM the following day.


We advise you to enter your diet diaries at a consistent time of day.

Are there any incentives for taking part in The APPLE Study?

With the completion of The APPLE Study you will receive: 

  • A personal nutrition report based on your food intake. 

  • An invitation to attend a Webinar on “A Guide to Nutrition & Psoriasis” by our Consultant Dermatologist, Dr Thivi Maruthappu.


*Please note, we cannot offer nutrition reports unless the 4 24-hour diet recalls are complete.


Why did I not receive a nutrition report?

Nutrition reports can only be generated using The APPLE Study Intake24. This means 4 diet recalls need to be completed in order to obtain the nutrition report.

What are the possible risks of taking part? 

There are no foreseeable disadvantages or risks to participating in The APPLE Study.

Please note you will be asked questions on weight, medical history and psoriasis severity.  

You are welcome to contact the research team, if participation in The APPLE Study has resulted in significant distress. 

Should you wish to receive additional support or information, we encourage you to talk with a GP, Dermatologist, Rheumatologist or another health care professional.  

Further information and support on psoriasis can be found on  

What are the possible benefits of taking part? 

This study is your opportunity to participate in the first national study exploring diet and lifestyle in people living with Psoriasis in the UK. Participation in the study will not directly affect your psoriasis treatment. We hope the study will help us to guide patients with psoriasis on dietary choices.   


Will I receive a summary of the findings?

If you wish to receive a summary of the findings, you will need to select "Yes" for the option "I wish to receive a copy of the final report", during informed consent. 

What will happen to the results of the project? 

The results of The APPLE Study are intended to be submitted for publication within journals in the field of Dermatology and Nutrition, as well as presented at relevant conferences. This project will also be submitted as a component of a PhD thesis.  


Once the study is completed, we will be sharing the findings with the participants who wished to receive a summary. These findings will be also shared with the Psoriasis Association and on social media.  

What if I change my mind about taking part in the study?

You are able to withdraw your data from the project up until December 1 2023, after which withdrawal of your data will no longer be possible because the data would have been committed to the final report.  


To withdraw from The APPLE Study please contact  the Research Nutritionist (Sylvia Zanesco) at with your name and the email address used to complete the online survey. If you choose to withdraw from the project we will not retain the information you have given thus far.  

How is the study being funded?

This project is being funded by the Psoriasis Association. 


The Psoriasis Association 
Dick Coles House 
2 Queensbridge 

​​How will my data be handled?

Your data will be processed under the terms of UK data protection law (including the UK General Data Protection Regulation (UK GDPR) and the Data Protection Act 2018).  

  • All the information collected from the online questionnaire responses will be kept confidential, stored securely on the King’s College London intranet platform, and handled in line with the data protection guidelines. 

  • The principal investigator is responsible for handling and storing the data during and after the study. 

  • The personal details provided (your name and email address) will be removed from analysis and your data will be de-identified. 

  • No participant will be personally identified in any report or publication. 

  • Research data will be retained for a maximum of ten years on completion of the study. This is in accordance with the KCL Records and Data Retention Schedule. 

  • The data will only be shared within the research team.  

  • Only the research team will have strict access to the data. 

  • The data will not be shared outside of the EU. ​

If you would like more information about how your data will be processed under the terms of UK data protection laws please visit the link below: 

bottom of page