Which diet is best for weight loss
When it comes to diets, new weight loss fads seem to be popping up quicker than you can say hungry, but how do you know, which one is really going to work? We had our resident nutritionist round up four of the most popular fads going around to see how they each stacked up.
Wondering if you should count calories or macros? Cut out carbs or fats? What about intermittent fasting, or dare we say it, go vegan? Maybe we should just ditch all ‘diet’ mantras and eat intuitively? Ask anyone what method to use for weight loss, and you’ll probably get a mixed bag of responses. With so many options, each claiming to be superior, it’s no wonder most of us are left confused.
As frustrating as this may be, when it comes to weight loss, there is no single ‘diet’ or eating plan that succeeds every time. In fact, the most successful option for you is likely to be different to the option that works for your friend, and different still, from your personal trainer.
So – how do you know which diet or eating plan is right for you? We’ve reviewed four of the most popular dieting trends for you to consider:
Calorie restricted method
In order to lose weight, your daily energy intake (measured in calories or kilojoules) must be lower than your daily energy expenditure, creating an energy deficit. Achieving a mild to moderate calorie deficit each day is the focal point of any calorie restricted diet plan. As everyone’s daily energy needs are different, calculations to estimate your unique energy target for weight loss can be performed by a dietitian or smart technology (i.e. BIA scales). In order to reduce your intake to match these targets, you might follow a set calorie meal plan, track your food and calorie intake using a smartphone apps, or follow a dietitian’s advice for modifying your daily food intake (i.e. portion size guidelines).
Things to consider:
Calorie restriction is a proven method for achieving weight loss, and often involves adopting healthy habits. For example, preferencing foods high in protein and fibre, preparing home-cooked meals, reducing non-hungry eating, and expanding food knowledge. However, tracking calories and/or following a calorie restricted plan can become time consuming, challenging and unsustainable. It can also lead to anxiety around food choices, particularly when eating out, which can interfere with your social life. Furthermore, the body can respond to energy restriction by increasing hunger hormones and reducing satiety hormones, making it difficult to stick with long term.
Intermittent fasting involves restricting food intake on certain days of the week or within certain hours of each day. Some popular intermittent fasting regimes include:
- The 5:2 diet – restricting calorie intake to approximately 800 calories on two consecutive days during the week. On the other 5 days, a normal balanced food intake is encouraged.
- The 16:8 – involves fasting for 16 hours and eating during an 8 hour window per day (i.e. between 10am and 6pm)
Things to consider:
According to research, intermittent fasting is equally as effective as traditional calorie restricted diets for achieving weight loss, not more so. However, some people find they get better results with intermittent fasting, particularly those who have tried traditional calorie restricted diets in the past with limited success, and/or are experiencing (or have experienced) weight loss plateaus. Also, intermittent fasting diets are typically more flexible when it comes to treat foods, and many people find living with a heavier restriction ‘sometimes’ more sustainable than a moderate restriction ‘always’.
However, intermittent fasting doesn’t always fit into everyone’s lifestyle. You may find it difficult to incorporate fasting into your routine, particularly if you have long, busy days. If you are very active, experience headaches or fatigue, have insulin requiring diabetes, have other chronic health conditions, or if you are pregnant or breastfeeding, this may not be a safe option for you. Also, if you feel tempted to overeat during non-fasting periods, or if you have a history of binge eating, this may not be the best solution for you.
Low carbohydrate diets
Low carbohydrate diets are usually described as having <50-65g carbohydrate per day, sometimes even as low as 20g. According to the Australian Dietary Guidelines, typical carbohydrate intakes range from 240-350g per day for males and 170-240g per day for women. The aim of a low carb diet is to allow the body to switch from using carbohydrates to using stored body fat as the main energy source (i.e. ketosis).
Things to consider:
Low carbohydrate diets can be incredibly effective for weight loss, with results usually surpassing traditional calorie restricted diets in the short term. This may have to do with the high satiety factor of proteins and healthy fats, and the ‘ketosis’ effect of lowering appetite. Low carbohydrate diets generally don’t enforce a calorie target, so followers enjoy the ability to ‘eat to appetite’. Weight loss aside, low-carb diets seem to have a competitive edge when it comes to lowering blood sugar levels, increasing HDL ‘good’ cholesterol, and reducing triglyceride levels.
However, low carb diets can be incredibly restrictive - eliminating entire food groups such as wholegrains, legumes, starchy vegetables, most fruits and most dairy. What’s more, these ‘banned’ foods offer essential nutrients such as calcium, pre-biotics, magnesium and fibre, so if you don’t plan your low-carb diet carefully, you may end up with a deficiency, compromised bowel health and constipation. Whilst some people thrive on low carb diets, others experience symptoms such as fatigue and headaches (i.e. ‘keto flu’), cravings, poor exercise tolerance, and compromised immunity. Some people may also experience an increase in their LDL (‘bad’) cholesterol, particularly when increasing intake of saturated fats from fatty red meat, processed meat, cheese, butter and cream.
Vegan, vegetarian and flexitarian.
Vegetarian diets involve cutting out meat, poultry and fish. Vegan diets restrict all animal products including meat, poultry, fish, dairy, eggs and animal derived products such as honey. Flexitarian is a new way of eating, whereby followers are vegetarian most days, and include animal products only sometime. People may choose to follow a vegetarian, vegan or flexitarian diets for ethical, environmental or health reasons, including weight loss. In fact, studies have linked plant-based diets with a lower body weight and body mass index (BMI) compared to other diets.
Things to consider:
Plant based diets appear to work for weight loss due to a natural, simultaneous reduction in calorie intake. In addition, plant-based diets are health promoting, in that they encourage an increased intake of fruits, vegetables, legumes, wholegrains, nuts and seeds. These foods are high in fibre and prebiotics, which support gut-health, and have been linked with reduced risk of type 2 diabetes, heart disease and some cancers.
However, careful planning is required to ensure appropriate intake of key nutrients found in animal products, including protein, vitamin B12, iron, zinc, omega 3 fatty acids, and calcium. When it comes to weight loss, it is especially important to consume adequate protein and fibre for appetite control. Also, simply eliminating animal products does not ensure good health – plant-based eaters still need to be mindful of their food choices, and restrict processed foods, in order to enjoy the benefits.
Choosing the ‘right’ one:
All of the above diets are effective weight loss strategies, and in the long term, they all appear to yield similar results. There is no ‘superior’ option here – and there are many other great options we haven’t covered, including intuitive eating and the Mediterranean diet. Our advice? Rather than selecting an option based on the end result, consider the journey. Do your research, and ask yourself these questions before starting any program:
Is this a plan you will enjoy following, somewhat?
Is this plan sustainable - can you see yourself following it for longer than a few weeks?
Is this plan achievable - will it fit easily into your lifestyle?
The most successful option is usually the one you can see yourself sticking to, pretty easily, long term, not the one that promises the most weight loss. We always advise that you speak with an Accredited Practising Dietitian to help you with the selection and planning process, to give you the best chance of success.