5 DIET TRENDS YOU NEED TO KNOW ABOUT

Dietary trends are eating patterns that become increasingly adopted over time and may become widespread across the general population, sticking around long-term. Some dietary trends appear quickly and disappear just as quickly. These diets can be very short-lived and are often referred to as a food fad or fad diet. Many people pursuing improved health or weight loss may look to try new and trendy diets. These diets often come with many promises. However, not all trends or fads live up to their health claims, sometimes having little or no evidence to support the claims. Unfortunately, some of these diets are not sustainable in the long term and can result in adverse health effects, yo-yo dieting, and even eating disorders. In this article, we look at some popular dietary trends, some that have good evidence for their use, some that have promising emerging evidence, and some that have no evidence at all and can be classed as a fad.

• 5:2 diet
• Intermittent fasting
• Paleo diet
• Ketogenic diet
• The Mediterranean diet.

5:2 DIET

The 5:2 diet is one variation of intermittent fasting that has been adopted quite widely as a means to accelerate weight loss.The eating pattern within a week is five days of normal food consumption and two non-consecutive days of lower calorie consumption, where a total of 500-600 calories is consumed. The 5:2 diet claims to help speed weight loss in some people and may also be easier for some people to follow when losing weight with benefits for people with Type 2 Diabetes. The evidence shows that this type of intermittent energy restriction can help as a weight-loss strategy and help manage blood glucose levels in people with Type 2 Diabetes potentially as effectively as continuous energy-restricted diets. Another benefit to the 5:2 diet is that it may be easier for some individuals to adhere to over the long term as continuous daily energy restriction can be challenging to maintain. Therefore, 5:2 may be a potential option for some individuals who are overweight or obese to implement as studies have shown effective weight loss using this method. The emerging evidence for the 5:2 diet is promising, so this trend may be here to stay and is one to watch.

INTERMITTENT FASTING (18:6)

The 18:6 diet is another variation of intermittent fasting (IF) that has been adopted as a means to induce weight/fat loss and improve health. The eating pattern can be anywhere from 6 to 8 hours of normal/regular food consumption and 16 to 18 hours of complete calorie restriction. People adopting this diet may choose to start with a shorter fasting window of 10-12 hours and reduce it to as low as 6 hours over time. During the fasting period, the only thing allowed is water, though some people allow tea or black coffee within the rules. IF claims to accelerate weight and fat loss, stabilise blood sugar levels and improve cognitive function. IF is also used to increase autophagy. Autophagy is a normal biological process occurring in the body that essentially cleans out old/damaged cells to generate new healthy cells. While some evidence for weight (fat) loss is promising, studies where IF vs continuous energy restriction were investigated found no differences between the groups regarding weight (fat) loss and that a calorie deficit in IF is still required. Evidence for IF in the treatment of diabetes and obesity also shows promise; however, longer-term studies are required as the current evidence base has generally been of short duration and small in size. Evidence for IF and the effect on the preservation of muscle mass is not yet apparent and requires more research. Increasing autophagy may have significant benefits for treating specific diseases like fatty liver disease, cardiovascular disease and cancer; therefore, with the current evidence looking positive, more extensive research is required to assess further. Evidence for IF for weight (fat) loss, health, and disease treatment is promising. It has also been widely acknowledged as a helpful strategy for some people to improve adherence to a weight (fat) loss plan as an alternative to continuous energy restriction.

PALEO DIET

The paleo diet is based on what is said to have been the human diet back in paleolithic times (2.5 million to 10,000 years ago). The diet excludes all foods that were introduced when modern farming practices were introduced around 10,000 years ago. The diet consists of:

1. Eating only whole, unprocessed foods, such as: Meat, fish, eggs, vegetables,

fruits, nuts, seeds, herbs, spices, healthy fats and oils.

2. Avoidance of any processed foods, such as grains, potatoes, dairy and legumes.

The paleo diet emulates our hunter-gatherer ancestors’ diet, whose digestive systems were designed for only whole, unprocessed foods that resemble what they look like in nature. The claim is that this is the ideal human diet that suits our paleolithic genetics. Whilst this diet promotes the consumption of whole foods, it also promotes excluding food groups (e.g. dairy) and nutritious foods. The paleo diet is over-hyped and under-researched and still lacks sufficient supportive evidence with health benefits that are inconclusive. Trend or fad? The paleo diet may have benefits due to the high consumption of whole foods and limiting of processed and refined foods; however, it still excludes food groups and nutritious foods, which lands it in the fad category.

KETOGENIC DIET

The ketogenic diet is a high fat, low to moderate protein diet that limits carbohydrate significantly so that the body goes into a state of ketosis (the body burns fat instead of sugar for energy). Dietary fat intake can be as high as 70-80% of total daily energy, with carbohydrates at 5% (sometimes up to 10%) of total energy, which can be as low as 20g per day. The diet avoids carbohydrate-rich foods such as bread, cereals, rice, pasta, fruit, potatoes, corn and peas. The claim is that the limited carbohydrates in this diet put the body in a ketosis state, which means the body will burn fat for fuel instead of relying on glucose. The diet is controversial as it promotes a very high fat intake which goes against the Australian Dietary Guideline’s recommendations. Ketogenic or high fat, very low carbohydrate diets were originally developed to treat epilepsy, and there is now some evidence to support its use clinically in the treatment of Type 2 Diabetes and obesity. The drawbacks of a ketogenic diet are lower dietary fibre intake and reduced energy levels, with weak evidence to support any performance benefits in athletes. More evidence is required to further the understanding of this diet as high-quality evidence is lacking. Clinical advice should be sought out if a ketogenic diet is being considered to follow.

THE MEDITERRANEAN DIET

The traditional Mediterranean diet is a healthy and balanced eating pattern based on the traditional diets (pre-1950s) of the people living near the Mediterranean Sea, with countries including Greece, Italy and Spain. This diet is abundant in whole foods, high in plant foods and minimally processed foods. More specific recommendations include:

• Whole grains and legumes in high quantities
• A wide variety of colourful, fresh vegetables
• Fresh fruit daily
• Cold-pressed extra-virgin olive oil as the primary source of dietary fat
• Small amounts of nuts and seeds
• Moderate consumption (at least 3 serves per week) of fish, including oily fish, at
• least once per week
• Poultry in moderate amounts 1-2 times per week
• Dairy products in low amounts
• Red meat once per week (or every two weeks)
• Low consumption of sweets, preferably based on nuts, honey and fruits, and
• less than three times per week

A large body of evidence exists due to the extensive research conducted over the last two decades on the traditional Mediterranean diet. The diet is strongly associated with a reduced risk of numerous chronic diseases and providing multiple health benefits. These benefits include a reduced risk of cardiovascular disease, atherosclerosis, metabolic syndrome, cancer, obesity, Type 2 Diabetes, and even increased longevity. The Mediterranean diet is widely recommended as a healthy and balanced approach to eating as it includes all food groups and is classed as safe and reasonably straightforward to follow. Diet trends and fads can often become confusing for people to navigate. There is not a ‘one size fits all’ diet. Health history, medications, current eating habits, physical activity levels, and goals are all factors to consider. The simplicity of a healthy balanced diet can become blurred under the flashing lights of the next big diet trend or fad, especially when an individual is striving to achieve a health goal. Sticking to the Australian Dietary Guideline’s basic recommendations should always be considered, as these have remained a dependable and trusted resource for many years.