It’s a jungle out there! So many articles, books, podcasts and self-professed ‘experts’ on the subject of the best-ever diet. Who’s to know what to believe? So, Jess, our very own Consulting Dietician, has lent a hand to provide some insights on some popular diets you will have heard of.
What is intermittent fasting?
Intermittent fasting is a dietary pattern where food intake occurs in a specific eating window. Outside this window, it’s time to fast (refrain). Often this is daily, such as a 16 hour fast followed by an eight hour eating window. Another common approach is the 5:2 diet where you have five days of unrestricted eating. This is then followed by two days where you eat a very low calorie diet (often around 500 calories).
What is the evidence?
Research on intermittent fasting is still ongoing, so we don’t yet have a full picture of the risks and benefits. However, so far the evidence for weight loss is no better than a calorie controlled diet.
A dietitian’s thoughts
This eating pattern is quite restrictive and may lead to overeating or binging during the eating window. So, in short, this won’t help with weight loss. From a safety perspective, this diet cannot be recommended for people with a history of eating disorders and may not be suitable if you have diabetes (depending on your medications).
What is a ketogenic diet?
A ketogenic diet is a very low carbohydrate diet, with moderate protein and high fat intake. Several popular diets fall under the umbrella of a keto-style diet, including the Atkins diet, the Banting diet and the South Beach diet. An example of a keto breakfast might be bacon, eggs and avocado. This is clearly not the diet for a vego!
The main concept of the diet is that by reducing your carbohydrate intake (which supplies glucose (a sugar) to your cells), your body has to use a different energy source, called ketones. Ketones are sourced from your body’s fat stores, so you are metabolising fat.
What is the evidence?
The keto diet was initially developed to help manage seizures in childhood epilepsy. Various versions now exist, often with a more moderate carbohydrate intake than on a “true” keto diet. Carbohydrates are still limited, however, to 20-50 grams per day. For context, a medium sized banana (170 grams) has 22 grams of carbohydrate.
For weight loss, a keto style diet is no more effective in causing weight loss than a low fat diet.
A dietitian’s thoughts
Commonly, the keto diet promotes intake of high saturated fats (like animal fats), which have a negative effect on cardiovascular disease risk due to their impact on LDL (“bad”) cholesterol levels.
The long-term reduction in carbohydrate intake also limits fibre intake, which has negative effects on gut health and may also cause constipation.
Another result of eating very limited fruits, vegetables and wholegrains in the long-term is the possibility of nutrient deficiencies, particularly B group vitamins, vitamin C and minerals such as selenium and magnesium.
What about Pilates?
It’s important to couple good eating with regular exercise and movement. This ensures a more effective, balanced and sustainable approach to maintaining your weight. Pilates is brilliant for supporting lean/muscle tissue as you lose weight, not to mention the mental health benefits. It’s also varied, which is important when it comes to exercise, we need to ensure we don’t just stick to the same old routine.
If you haven’t yet experienced the amazing benefits of reformer Pilates, you need to dive in and see for yourself! Reform Studios in Mitchelton runs a introductory class for those looking to start: Reformer Fitness Intro.
These eating patterns have become popular in the past few years, particularly for weight loss. The key for long-term weight maintenance is finding something you can do forever. For example, intermittent fasting is unlikely to work for someone who loves going out to breakfast on the weekend.
Similarly, a keto diet isn’t likely to work for someone who loves breads, pastas and potato (don’t we all?). When we choose to follow a diet that doesn’t align with our lifestyle and food preferences, often we can fall into the trap of being “on a diet” (where you follow a certain structure until it does work or appeal to you anymore) and being “off a diet” where you return to your normal eating habits. This return to old habits leads to weight regain – common sense, right. When you were eating that way previously, it supported your previous weight, so returning to that pattern generally means a gradual return to that weight.
About the author: Dr Jess McMaster is an Accredited Practising Dietitian with a background in weight management. Jess is passionate about the prevention and treatment of chronic lifestyle diseases such as obesity, diabetes and cardiovascular disease. Having submitted her PhD thesis in 2019, focused on a minimally invasive weight loss treatment and its effects on gut function and the gut microbiome, she is now able to apply her knowledge in a clinical setting. Jess is a passionate foodie, and loves to cook dishes that remind her of her overseas travels.