We’re all familiar with the steady stream of new diets that all promise to be the best for weight loss success. Although many may yield short term weight loss, the success rate for weight loss maintenance remains low for most people. Indeed, most people regain all the lost weight and often more, within 6-12 months.
However, new research brings hope of these fad diets becoming a thing of the past, with experts predicting that a personalised diet approach will transform the way people lose weight.
What determines success?
Scientists have dismissed the belief that getting off track is merely down to a lack of willpower. Rather, they assert that ones individual make-up; that is, their genes, hormones and psychology play the biggest role. The theory is that instead of reaching for a one-size-fits-all diet, people should follow one that is tailored to their individual needs.
Leading obesity experts along with the BBC Science team, have recently put this theory to the test. Over three months, 75 dieters were put through a series of tests and monitored at home.
The study assessed three types of overeaters:
- 1) Feasters who find it hard to stop eating once they start
- 2) Constant cravers who feel hungry all of the time and
- 3) Emotional eaters who turn to food when they get stressed or anxious.
What did they find?
In regards to feasters, it was shown that their hormones play a big part in their eating habits. Specifically, feasters produce low levels of certain gut hormones that are released when food arrives in the intestines. These chemical signals travel through the blood to the brain and tell the body when it has had enough food and should stop eating. Interestingly, some people have incredibly low levels of certain gut hormones and are not getting those signals to stop eating.
Constant cravers on the other hand, always want to eat and their “hungry brains” often want fatty and sugary foods. Scientists know that certain genes make people very hungry. Unfortunately for constant cravers, this disrupts the way signals are sent to the brain telling it to stop eating, tricking the brain into thinking that fat stores are continually in need of replenishment.
Finally, emotional eaters reach for food when they are feeling stressed or anxious. When the brain detects this feeling it triggers changes to the body, increasing the heart rate and placing the body in a heightened stress state. Unfortunately for emotional eaters, these developed habits are incredibly difficult to break, as when they become stressed their brains are conditioned to reach for a reward in the form of food.
So, what diet should each group follow to successfully lose weight?
- Feasters are advised to eat a diet that keeps them feeling fuller for longer. A high protein, low GI diet is recommended as it will also boost gut hormone signals. Food such as fish, chicken, basmati rice, lentils, grains and cereals are best, while potatoes and bread should be avoided, or at least minimised as they will not keep hunger at bay for long. Protein and carbs that are not absorbed quickly are absorbed lower down the gut, producing more of hormones that make us feel fuller for longer.
- Constant cravers have genes that lead them to feel hungry most of the time and therefore, find it incredibly difficult to maintain a diet for seven days a week. In recognition of this, they are advised to drastically reduce their diet to 800 calories on two days of the week. Eating normally but healthily, for the other five days, this way of eating, increasingly growing in popularity, is known as the 5:2 diet, or intermittent fasting. Unfortunately for constant cravers, they have a strong predisposition to being overweight and it’s thought that the fasting diet should shock their bodies into burning fat.
- Emotional eaters have typically established bad habits that are difficult to break. Group support combined with following a healthier diet, is thought to yield the most success for these individuals. Encouragement from others can trigger the motivational part of the brain that helps people overcome stress and therefore reduce the food for comfort behaviours.
The consistent behaviours of successful dieters:
The study also confirmed the behaviours that increase the likelihood of weight loss maintenance success in all people, regardless of which category they fall into:
- Eating slowly to increase the level of the gut hormones that tell the brain to stop eating.
- Always eating breakfast. Eating breakie has been shown to decrease cravings for bad food.
- Eating thick soup. When know that a hearty soup makes you feel fuller for longer. This is because thick soup stretches the stomach and crucially stays there longer. Scientists say thick soup fills you up more than solid vegetables.
- Not shopping when hungry. Tiredness influences decision making and can increase a desire for unhealthy foods, so it’s best to write shopping lists and avoid doing the groceries when hungry.
The effect of exercise on dieting
Interestingly, the study found that while exercise can indeed help people lose weight, there is a catch. Often individuals are less active after exercise, negating much of the hard work they have done! This led the scientists to conclude that the most effective way to lose weight is nearly always to change your diet.
How successful was the personalised diet approach?
Each of the three groups were challenged to lose 5% of their body mass- they surpassed this, losing 8%. Constant cravers had the hardest job and feasters lost the most.
Importantly, the dieters expressed great relief at discovering why they find it so difficult to lose weight. They finally understood why their biology was working against them, and found this improved understanding very empowering.
So, while it is still early days for the science of personalised diets, it appears that there is huge potential is for this approach. Watch this space!
To find out more about this study you can watch the video here – What’s The Right Diet For You? A Horizon Special.