Nearly two thirds of UK adults are classified as overweight and just over a quarter are classified as obese. With the endless minefield of information on the net about the most effective way to lose weight, it is easy to feel overwhelmed and not know where to start if looking to make a positive change. Conversations with GPs around weight tend to be doctor-led and arise from an individual presenting with a medical condition associated with weight gain. Due to time restrictions, guidance on how to go about losing weight can often feel rushed and inadequate in the GP setting. Not to mention the fact that the GP may not necessarily be trained in health behaviour change. Despite what influencers and celebrities may have you believe sustained weight loss is difficult and what works for one individual is not necessarily going to work for the next. The truth is what determines our weight is extremely complex. It involves an interplay between genes, family history, ethnicity, age, sex, hormones, and neurotransmitters (chemical messengers that enable nerve cells to communicate with each other), social factors and environmental influences.


Low Carb, No Carb, Low Fat, Paleo, 5:2, 16:8, WW, WFPBD, Mediterranean, DASH, Vegetarian, Vegan, – these are just some of the mainstream diets that you may already be aware of. There are of course hundreds more. So, what works? Research has shown that as far as weight loss is concerned the type of diet itself is not particularly important, rather it is the ability to stick to a sustainable eating plan. New diets tend to have a high failure rate. In fact, most people only tend to stick to a new eating plan for an average of 19 Days. A new dietary plan is deemed a success if an individual manages to keep weight off for over a year – even a couple of kilos has great benefits. A research study conducted in 2014 comparing various named diets showed statistically significant improvements in weight with all at the 1-year mark with marginal differences in effectiveness of each. The data suggests that it does not matter which eating plan you decide to go with as long as you can sustain that way of eating long term. If an individual, after embarking on a new eating plan, can get past the point of following a ‘diet’ and eventually transition to a stage in which the dietary change has now become a habit it shows promise for attaining the goal longer term. A diet which is too restrictive is likely to lead to early failure. With multiple failures this not only becomes increasingly disheartening but can also lead to an unhealthy relationship with food long term as well as exacerbating stress.


It is unlikely there is an optimum diet for all. Diet plans are very individual. It is important to consider the client’s medical problems and needs. A diet which is rich in classically healthful fibre rich foods such as broccoli and asparagus may not be agreeable to someone with irritable bowel syndrome, or a low-fat diet may not be the most suitable for a type 2 diabetic due to the disproportionate level of starchy carbohydrates that may be consumed as a result. It is also important to think about diets within a social and cultural context. For example, a 16:8 time-restricted feeding pattern (in which an individual fasts for 16 hours of the day and has all their meals in an 8-hour window) is unlikely to be sustainable in a night shift worker that works 12-hour shifts.


In short it depends on the goal and the person. Restrictive diets are more likely to fail. Despite this, however, a diet can provide a useful framework for some individuals to follow. This may particularly be the case if they are on a therapeutic diet due to a specific medical condition, if they have had a complex relationship with food in the past or simply if they are just unsure of which foods are healthy. In this regard non-restrictive diets such as the Mediterranean diet or a Vegetarian diet tend to be easier to follow long term and are more likely to yield a successful end-result.

An individual that simply makes the decision to eat ‘healthy’ with less refined foods, replacing them with a variety of fresh fruits, vegetables, nuts, seeds, legumes, and wholegrains, is just as likely to be successful if they can remain committed. These foods contain plant compounds, known as phytochemicals, which function as antioxidants which have been shown in numerous studies to combat various illnesses as well as having a positive effect on mental health. The better an individual feels with any change in eating habits, the more likely that he or she will continue in this way. The freedom to eat whatever one chooses within this broad array of food types can lead to a greater sense of empowerment which is likely to lead to sustained behaviour change.

It is also worth mentioning that many individuals that are trying to lose weight achieve results by calorie counting. Modern apps such as MyFitnessPal have made it a lot easier to track calories and achieve the desired calorie deficit by the individual as well as keeping an eye on the breakdown of macronutrients (carbohydrates, fats, and protein) within the diet. Again, this comes down to whether this is a method that the individual can sustain longer term.


Intrinsic motivation is the act of engaging in a change for the enjoyment and personal satisfaction of doing it, whereas extrinsic motivation arises from external benefits or rewards. The act of dietary change is often based on both. In general, extrinsic motivation is good for short term goals. In the context of dietary change, the driver for most is weight loss which tends to be extrinsically motivated initially. It is the positive reinforcement of having someone notice that you have lost weight which is important in the early part of the journey. Intrinsic motivation is more important for sustainability of the change long term so that it becomes a habit. As far as nutrition is concerned people who are intrinsically motivated find satisfaction from the physical and psychological components of being healthier rather than the outward changes that may be noticed. This tends to come later as it may not be strong enough at the outset to elicit change. Many extreme or drastic dieting plans fail as they are solely extrinsically motivated and fail to consider the complexities of human physiology and psychology. Repeated failures or yo-yoing can not only be detrimental to physical health, but take a toll on an individual’s mental well-being, as well lead to disordered eating patterns.


  1. Sustainability of the diet is the most crucial factor. Too many drastic changes from your baseline way of eating tends to be a recipe for failure. The easier the dietary change is to follow, the greater the likelihood of success. This may involve small stepwise changes
  2. There is no optimum diet. Though scientists may argue over which one is the most beneficial, it is worth noting those which have shown the most benefit share the same themes – that is a plant-focused way of eating which is rich in fruits, vegetables, nuts, seeds, legumes, and wholegrains.
  3. Incremental change is often the key to success. Having the motivation for wholesale change is hard in the context of a modern busy life.
  4. Be patient with yourself with a view to making one small change at a time. Making these changes using the SMART criteria (Specific, Measurable, Achievable, Realistic and Time-bound) will lead to greater gains in the long run.
  5. Whilst adopting a dietary change it is important not to neglect physical activity, good sleep hygiene and stress reduction. Via complex pathways these all play a role in which foods we choose to eat and how much we choose to eat.
  6. There is no reason that dietary change should leave us feeling hungry. Whole foods in the form of fruits, vegetables and whole grains tend to be the most satiating rather than refined food products. At the same time eating to true fullness is important. Eating more mindfully on a kitchen table rather than in front of the TV, allows us to acknowledge our own hunger signals to avoid overeating.
  7. Get the basics right first! Though there is exciting research relating to time restricted feeding and intermittent fasting, however embarking on this dietary change when a diet is high in refined unhealthy foods is unlikely to yield benefits for overall health. The first step should be incorporating more whole foods into the diet.
  8. Finally, food should be enjoyable. It is not worth making a change if you are not finding your food tasty. This is not conducive to long term success. Additionally, it can lead to a troubled relationship with food.


Comparison of weight loss among named diet programs in overweight and obese adults: a meta-analysis: JAMA 2014

Bradley C Johnston Steve Kanters Kristofer Bandayrel Ping Wu Faysal Naji Reed A Siemieniuk Geoff D C Ball Jason W Busse Kristian Thorlund Gordon Guyatt Jeroen P Jansen Edward J Mill