The Good, The Fad And The Ugly


  • Fad diets can be tempting as they offer short term solutions to a complex problem. However, they can lead to nutritional inadequacies such as energy and nutrient deficiencies.  
  • Claims that sound too good to be true probably are. 
  • Good nutrition is about healthy sustainable dietary behaviour.
  • Make healthier choices, eat a nutritionally balanced and varied diet with appropriately sized portions, and include daily physically activity. 
  • The best way to lose weight and keep it off is to combine an active lifestyle with healthy eating.
  • For credible nutrition advice, seek the expertise of a Registered Dietitian (RD) or Registered Nutritionist (RNutr).

Fad diets, what are they all about?

A fad diet refers to a dietary plan that promotes outcomes such as rapid weight loss or health advantages without robust scientific evidence to support its claims.  Often these diet plans involve restrictive eating patterns and the avoidance or elimination of food groups such as dairy or carbohydrates, despite not having a medical diagnosis such as coeliac disease which requires a gluten-free diet or ketogenic diet for seizure management and certain metabolic disorders. 

A fad diet might instruct what types of foods you eat such as juice cleanses, the Paleo diet, the raw food diet and also when you eat them such as fasting regimen diets.  The removal of whole food groups and severe energy restriction can increase the risk of nutrient deficiencies or energy deficiency.  

For example, the Carnivore diet which consists entirely of meat and animal products and excludes all other foods can lead to inadequate intake of carbohydrates, fibre and many vitamins, while being high in saturated fat which is an unhealthy balance of nutrients for cardiovascular and gut health.  Juice cleanses are low in calories, protein, fat, calcium, iron, iodine, selenium and vitamin B12. 

Furthermore, diets that require a fixed calorie intake or specific foods may be particularly challenging for those on low income for reasons such as food availability, accessibility and affordability[1, 2].

New Year, New Me

With a new year comes the tradition of making New Year’s resolutions as people tend to think about future goals for self-improvement.  According to a Healthy Ireland survey 90% of people in Ireland indicated a desire to make at least one change in their lives to improve their health and wellbeing[3]. January sees trends for detoxes, cleanses and extreme weight loss diets thrive as this tradition becomes an opportunity for the commercialisation of new products or services.  

Fad diets are unsustainable long term and often give people a false sense of hope when initial weight loss is achieved.  Weight regain is common following voluntary attempts of dieting and is often greater than the weight lost during the dieting period[4-7]

The influence of social media

Social media and other advertising platforms play a role in influencing the adoption of lifestyle behaviours or social norms[8].  With health information often presented on social media it can be hard to tell whether social media is our friend or foe[8, 9].  Fad diets tend to be popularised by celebrities, social media influencers or even by doctors and scientists endorsing brands to promote their food products, ingredients and/or supplements with alleged health advantages.  High-profile endorsements are often paid with the goal to encourage customers to purchase products, supplements, diet plans or books and provide the influencer with a self-marketing opportunity. 

As an increasing number of people are using social media apps to help with their weight loss goals, it is important to remember that health information provided on these platforms may not be evidence-based.  For credible nutrition advice, seek the expertise of a Registered Dietitian (RD) or Registered Nutritionist (RNutr).

Ways in which you can follow a healthy diet

A Healthy Ireland survey on weight reported that 23% of people in Ireland were living with obesity in 2021, 10% greater than the European Union average[3].  Just over a third (35%) were trying to lose weight, with 49% of those who were overweight or living with obesity currently trying to lose weight[3].  Weight loss is complex and lifestyle changes such as diet and physical activity should be tailored to meet each individual’s energy needs and food preferences.  For weight related goals, whether it’s for health reasons such as obesity and associated comorbidities or to feel good in yourself, there are many ways in which you can follow a healthy diet:

Having a healthy and enjoyable relationship with food is essential – after all it is one of the finer things in life.

Contributed to by Saoirse Farren, 3rd Year student, Public Health Nutrition, GMIT.


  1. Pitt, E., et al., Exploring the influence of local food environments on food behaviours: a systematic review of qualitative literature. Public Health Nutr, 2017. 20(13): p. 2393-2405.
  2. Daniel, C., Is healthy eating too expensive?: How low-income parents evaluate the cost of food. Soc Sci Med, 2020. 248: p. 112823.
  3. Healthy Ireland, Summary Report, Department of Health, Editor. 2021, Government of Ireland: Dublin.
  4. Frühbeck, G., et al., The ABCD of Obesity: An EASO Position Statement on a Diagnostic Term with Clinical and Scientific Implications. Obes Facts, 2019. 12(2): p. 131-136.
  5. Langeveld, M. and J.H. de Vries, The mediocre results of dieting. Ned Tijdschr Geneeskd, 2013. 157(29): p. A6017.
  6. Dulloo, A.G., J. Jacquet, and J.P. Montani, How dieting makes some fatter: from a perspective of human body composition autoregulation. Proc Nutr Soc, 2012. 71(3): p. 379-89.
  7. Wilborn, C., et al., Obesity: prevalence, theories, medical consequences, management, and research directions. J Int Soc Sports Nutr, 2005. 2(2): p. 4-31.
  8. Spadine, M. and M.S. Patterson, Social Influence on Fad Diet Use: A Systematic Literature Review. Nutr Health, 2022: p. 2601060211072370.
  9. Jane, M., et al., Social media for health promotion and weight management: a critical debate. BMC Public Health, 2018. 18(1): p. 932.

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