1 January 2024

A New Year, A New Diet?

Dieting is arguably the most popular indoor sport for Aussies and with 2024 now here, losing weight and getting healthy may be part of your New Year’s resolution. Popular diets have gained widespread attention on social media and is the topic of conversation for many influencers and celebrities. Unfortunately, many diets are ‘fads’ with minimal scientific evidence to support health claims. They can also be potentially harmful and unsafe if not used in the right circumstances. There is also evidence to suggest that weight loss diets don’t work in the long term and may eventually lead to weight gain. A meta-analysis of 29 long-term weight loss studies found that more than half of the lost weight was regained within two years and by five years more than 80% of lost weight was regained.[i]

The question that may come to mind is what is the best diet to lose weight that is based on scientific evidence?  To help answer this question and help you make an informed choice, Dietitian, Rebecca McPhee, has put the spotlight on 6 popular diets, exploring the pros and cons of each one.


A very low carbohydrate, fat rich diet that was used to treat children with epilepsy back in the 1920s. This diet works on the premise that to lose weight, your body must use ketones from fat as the primary energy source instead of glucose from carbohydrates.

  • A therapeutic option for paediatric epilepsy
  • Short term weight loss
  • Lacking important nutrients including vitamins, minerals and dietary fibre from fruit, vegetables, wholegrains, and legumes
  • Gastrointestinal issues from inadequate fibre including constipation, bloating and an imbalance in gut’s microbial composition
  • Very high in saturated fats from cream, butter, and fatty meats. A high saturated fat diet has been linked to increasing the risk of ‘bad’ LDL cholesterol
  • A high fat, low fibre diet can increase the risk of kidney stones
  • Cognitive decline. The effects of very low carbohydrate eating on brain metabolism can potentially lead to cognitive decline
  • Side effects from ketosis such as bad breath and fatigue
  • Difficult to sustain long term
  • Unknown long-term health effects



Low carb diets gained widespread attention in the early 1970s when Dr Robert Atkins wrote a bestselling book ‘Dr Atkins Diet Revolution’. Low carb diets restrict carbohydrate containing foods including bread, grains, pasta, starchy vegetables, and some fruit. Low carbohydrate eating results in weight loss because carbohydrates are stored in the body with water, therefore initial weight loss is mostly water.

  • Improvement in diet quality in that consumption of low fibre, highly processed carbohydrate foods are limited. This reduces the overall intake of calories, sugar, and sodium.
  • Short term weight loss
  • Improvement in blood sugars for some people living with Diabetes
  • May be difficult to sustain in the long term, depending on how low the intake of carbohydrate intake is
  • Lacking important nutrients including fibre and healthy gut bacteria from wholegrains, legumes, fruit, and vegetables
  • Fatigue and headaches
  • Long term health effects are unknown



Fasting is not new and has been practiced for thousands of years in different cultures for a range of reasons. However, in recent years, fasting has become a popular diet trend promoting weight loss and other health benefits. In particular, the 5:2 diet by Dr Michael Mosley gained a lot of media attention. The 5:2 regime is intermittent fasting which involves 5 days of healthy eating and 2 days of caloric restriction (500-600 calories) or ‘fasting’. Following the success of 5:2, the 16:8 has also gained popularity as a fasting alternative. The 16:8 plan involves eating during an 8-hour period followed by a 16-hour fasting window. This method of fasting is known as ‘time-restricted eating’.

  • Short term weight loss
  • Health benefits: Improvements in several health markers including lowering blood pressure, blood sugars, blood cholesterol and lipid levels, resting heart rate and inflammatory markers
  • Flexibility: there are many types of fasting regimes so you can choose a plan that suits your lifestyle
  • Potential nutrient deficiencies. Depending on the type of fasting regime, meeting your daily nutrient needs may be a challenge. It is imperative that well balanced meals are included during the eating periods.
  • Adherence challenges: fasting will only work if you stick to it! Long term fasting may not suit some as it requires discipline and planning.
  • Side effects. Long-term fasting or skipping meals may lead to hunger, irritability and fatigue and therefore be difficult to sustain long term. People with certain medical conditions such as Diabetes, pregnancy, breastfeeding, growth periods (Adolescence) or a history of eating disorders may not be suitable candidates for adopting a fasting type of regime.



The alkaline diet has come back into fashion after several celebrities, claimed to benefit from following this regime. The theory suggests that the foods we eat affects our body’s pH balance. The pH measures how acidic or alkaline something is. Eating ‘acid producing food’ such as meat, dairy and grains causes an acidic environment in the body and therefore leads to metabolic disturbances and disease. On the other hand, an alkaline diet which includes vegetables, fruit and nuts makes the body more alkaline and promotes health.

  • Restricts processed foods typically high in sugar, sodium, and trans fats
  • Promotes healthy foods choices including vegetables, fruit, legumes, and nuts
  • Little evidence supports this regime including the theory on acidic base foods being health harming. The fact is that food has little effect on the pH of the blood. Parts of the body need acidity to digest food properly e.g., stomach and can naturally balance its pH
  • Potential nutrient deficiencies including inadequate protein needed for tissue growth, repair and immunity, b group vitamins from limiting grains and calcium/vitamin D from eliminating dairy
  • It may promote an unhealthy focus on certain foods [ii]



The CSIRO Total Wellbeing Diet is a nutritionally balanced, higher protein, low GI eating plan that has been scientifically tested in many studies.

  • Higher protein meals and lower GI carbohydrates help control appetite, tackle cravings, and reduce feelings of hunger.
  • Does not eliminate food groups so nutritionally balanced with a wide variety of food choices for the whole family
  • The low GI diet assists with sustainable weight loss and has also been connected to better blood sugar and insulin control, disease prevention, increased energy, and improved mood.
  • Data has shown that on average people who complete the 12 Week CSIRO Toal Wellbeing Diet Program lose 7.2% after 12 weeks, 9% after 6 months and then maintain their weight loss for the remainder of the year.
  • None!



One of the world’s oldest and healthiest eating patterns making it an all-round winner. It is also recognised by the World Health Organization as a healthy and sustainable way of eating. What makes up a Mediterranean diet:

  • A high consumption of cereals, legumes, nuts, vegetables, and fruits.
  • A relatively high fat intake, mostly provided by olive oil which are unsaturated ‘good’ fats
  • A moderate to high fish intake
  • Poultry and dairy products consumed in moderate to small amounts
  • A low consumption of red meats and meat products
  • A moderate alcohol intake, usually in the form of red wine
  • The Mediterranean diet is not just about the type of food eaten. It also involves social and cultural factors such as eating with friends and family, post-meal siestas and lengthy mealtimes. These habits promote positive social connections and a less stressful, more relaxed way of living.
  • Associated with a reduced risk of various lifestyle related diseases including heart disease, obesity, diabetes, dementia, and some cancers.
  • linked to longevity making it one of the best diets as we age [iii]
  • No food groups are banned! The diet focuses on plant foods, healthy fats and a small amount of dairy products. You can even enjoy red wine, in moderation!
  • You can make the Mediterranean Diet even healthier by choosing low Glycemic Index (low GI foods) including wholegrain bread and cereals, pasta, low GI rice, lower GI potatoes, fruit and vegetables.
  • None!




Swap breads and cereals to low GI, wholegrain choices


Drop white potato and choose lower GI potato or sweet potato


Add lots of seasonal salad or vegetable to every meal


Reduce amount of carbs at meals to a ‘fist size’ portion

If you want to try incorporating more low GI, Mediterranean-style foods into your diet, consider these for your next shopping trip. Shopping list.

We also have a 7 day low GI Mediterranean meal plan packed with delicious recipes which you can access for free. [iv]


By Rebecca McPhee, Accredited Practising Dietitian (APD) & Health Coach Consultant.


[i] Hall, K. and Kahan, S. Maintenance of lost weight and long-term management of obesity. Medical Clinics of North Amero. 2018 Jan; 102(1): 183–197.

[ii] dietitiansaustralia.org.au

[iii] Martini, D. Nutrients. 2019 Aug; 11(8): 1802

[iv] gisymbol.com

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