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Clementine Vaughan, registered dietitian and nutritionist in London

Hi, I’m Clem, a.k.a your Third Sister

Registered Dietitian & Holistic Health Nutritionist in London

Growing up in a British-French household, food was central to our upbringing. It served as more than sustenance; it was a gathering point where we connected as a family and shared our lives. This upbringing cemented my belief that food goes beyond nutrition—it’s steeped in culture, tradition, emotion, and much more. Fascinated by our relationship to food and its impact on our overall wellbeing, I pursued a career as a women’s dietitian & nutritionist in London to help others rediscover the transformative power of food

I graduated from Bristol University in 2011 with a degree in neuroscience. Subsequently, I earned a Master’s in Nutrition and a PG Dip (Postgraduate Diploma) in Dietetics from King’s College London. I am registered as a Dietitian with the HCPC, and I became a member of British Dietetics Association (BDA) in 2017. My career spans the Food & Beverage and FoodTech industries across the UK and Asia.
Third Sister founder Clementine Vaughan, a registered dietitian specialising in women's nutrition and holistic health

Who is the Third Sister?​

I am the youngest of three sisters and therefore, the Third Sister. My women’s dietetics & nutrition practice was born from a desire to help women face their health struggles through nutrition and diet.

From adolescence, I dealt with the constant pressure to maintain a certain image while keeping up with a fast-paced lifestyle. In my early thirties, I experienced work-related burnout and struggled to implement a healthy routine, despite my knowledge as a registered dietitian. The burnout brought to light a lot of deep-seated insecurities and unhelpful habits, as well as other health issues I had normalised and ignored.

Taking time to reassess my lifestyle and starting with baby steps, I made small, meaningful changes to support my health goals. These changes slowly led to exponential improvements, and I eventually regained my health and confidence.
Nutritious women's meal demonstration to Third Sister clients

Through my own experience, I discovered the powerful ability of food to nourish and heal. My life transformed when I understood what was healing versus hurting both my body and brain—this formed the foundation and approach for my work as a holistic health nutritionist & dietitian.

My story is not unique. Countless women face similar struggles, though the triggers and symptoms that manifest may differ. Third Sister is more than a practice—it’s a sisterhood where women can find support and reclaim their health and confidence through the power of food. As a women’s nutritionist & dietitian, I specialise in creating tailored plans that meet hte unique needs of every woman.

Explore Third Sister's services

Our Areas of Expertise

Whether you're seeking a nutritionist in London or an online consultation, I’m here to help you explore the powerful connection between food and health.​

Third Sister provides personalised, science-led dietetic plans for women of all life stages and conditions. We specialise in a range of women's health issues, including:​

Weight Management

From lifestyle changes to nutritional support for medicalised weight loss (e.g. Ozempic, Munjaro)


Hormonal Health

PCOS, endometriosis, fibroids, menopause.

Digestive Health

SIBO, IBS, other gut concerns.

Pregnancy & Postpartum

Healthy eating at each trimester of your pregnancy and postpartum renourishment to support post-pregnancy goals.

Lifestyle & Wellness

Personalised healthy meal planning and family nutrition.

Our Credentials

The British Dietetic Association logo
The Registered Health and Care Professions Council UK Logo
The British Dietetic Association's 'Trust a Dietitian' campaign logo

Schedule a free initial assessment to see how we can address your concerns.​

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