Intermittent fasting delivers results for women with obesity

Amanda Lyons

10/01/2019 2:02:22 PM

Research has found women with obesity who followed a strict diet involving intermittent fasting lost more weight than those undertaking other methods.

The University of Adelaide study found women who followed a diet in which they ate 70% of their required energy intake and fasted intermittently lost the most weight. (Image: World Obesity image bank)
The University of Adelaide study found women who followed a diet in which they ate 70% of their required energy intake and fasted intermittently lost the most weight. (Image: World Obesity image bank)

It seems like everybody is talking about the ‘diet trend’ that is intermittent fasting, including Hollywood stars.
But is it just another food fad, or a genuine tool to promote health and weight loss?
A University of Adelaide study recently published in the journal Obesity provides strong support for the latter.
The project followed a sample of 88 women aged 35–70 with a body mass index (BMI) in the 25–40 range as they followed carefully controlled diets over 10 weeks.
‘Continuously restricting their diet is the main way that obese women try to tackle their weight,’ Dr Amy Hutchison, the study’s lead author from the University of Adelaide and the South Australian Health and Medical Research Institute (SAHMRI), said.
‘Unfortunately, studies have shown that long-term adherence to a restricted diet is very challenging for people to follow, so this study looked at the impact of intermittent fasting on weight loss.’
The researchers also contrasted different diets and regimens in order to provide a comparison.
‘Obese women who followed a diet in which they ate 70% of their required energy intake and fasted intermittently lost the most weight,’ Dr Hutchison said.
‘Other women in the study who either fasted intermittently without reducing their food intake, who reduced their food intake but did not fast, or did not restrict their diet at all, were not as successful in losing weight.’
The most successful study participants lost around 0.5–1 kg for each week of the study, a result that delivered significant health benefits, such as decreased markers for heart disease.
Dr Tri Cao, a GP with a special interest in obesity research and education, agrees that the evidence supports intermittent fasting as a viable option for patients with obesity.

Dr-Tri-Cao-text.jpgDr Tri Cao agrees that intermittent fasting can be used as a health weight loss strategy for patients with obesity.
‘The health benefits of intermittent and periodic energy restriction are well-known, accepted and practised by obesity physicians,’ she told newsGP.
‘[It can be practised] within a week; for example, 5:2, eating five normal days and two calorie-restricted days.  
‘Or within a day; for example, eat two normal meals in a period of eight hours, and fast 16 hours between meals with the patient either skipping breakfast or dinner.’
Dr Cao believes intermittent fasting is a good weight-loss method for GPs to recommend, as long as they bear in mind that it is important to tailor their advice to the patient.
‘There are many fad diets, and as a GP our first priority is to do no harm and help patients avoid these,’ she said.
‘I can say that, [done properly], intermittent fasting will do no harm to the patient, although of course we need to pay attention to those with chronic diseases such as insulin-dependent diabetes, or consider fatigue and temporarily disorientation during the fasting period in patients working with machines or driving.’
Dr Georgia Rigas, Chair of the RACGP Specific Interests Obesity Management network, agrees it is important to treat each person with obesity as an individual, especially when considering weight loss methods for recommendation.
‘We firstly need to acknowledge the heterogeneity that is obesity; meaning how it affects one individual will be different to how it affects the next individual,’ she told newsGP. ‘Therefore, it comes as no surprise that no one-size-fits-all approach in weight management is observed, just like in diabetes, asthma and other chronic diseases.
‘There will be some individuals who are good responders to a particular therapy – in this case, intermittent fasting – and others who are partial or non-responders. At present, there is no test we can perform to determine or predict which particular therapy an individual will respond to.’
Dr Cao also emphasises that while intermittent fasting can work well as a weight-loss tool, it should not be considered a permanent solution.
‘The most important issue in weight management is not which diet will work. The key success is the patient’s ability to comply with your recommendation, the sustainability of the method and eventually the healthy behaviour changes,’ she said.
‘If intermittent fasting is the patient’s choice, we can use it as a transition to achieve weight loss, limit weight regain, support and guide them to establish healthy behaviour and blend into a normal regular healthy diet.
‘Nobody can stay on this diet forever.’
Keen to further investigate fasting as a weight-loss tool, the SAHMRI research team is currently undertaking new trials to examine the effectiveness of long-term fasting on men and women.
But, as we await the results of these next trials, Dr Rigas highlights the importance of the GP’s role in providing support and instruction for a patient’s weight loss efforts.
‘Research indicates that the majority of individuals with overweight or obesity have already participated in at least two previous weight-loss attempts before they see their GPs,’ she said.
‘Many of these individuals have responded to the intervention they tried and were able to lose some weight, but struggled to keep it off. This is not because they have failed, are weak or lack moral fibre – quite the opposite. They are fighting their biology as it physiologically defends against weight loss, which is driven by hormones that are not under voluntary control.
‘This is when patients really should be seeing their GP for ongoing help, advice and support.’
Dr Cao agrees that GPs are key health professionals in helping support patients with weight-loss efforts.
‘Diets, meal replacements, medications, and even bariatric surgery are just weight loss tools. We cannot give patient tools without teaching them how to use them well,’ she said.
‘GPs are the game-changer in weight management. Unlike, for example, endocrinologists, hospital clinics, allied health professionals, patients have unlimited visits to see their GP.’

Intermittent fasting obesity University of Adelaide Weight loss

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Dr Hermann Meyer   11/01/2019 10:54:01 AM

“Nobody can be on this diet forever”
...and why not.?
That is exactly the beauty of this method in that it alters from effort to reward, thus does not lead to exhaustion over time. The intensity can be varied, but asting the need for weight management is in most cases life long. Fasting needs to be repeated as needed, just as it is in most religious traditions, where it is part of normal life. A single course of fasting will be no cure for obesity. The propensity to gain weight is not altered. But at least we can supply the patient with a tool that is useful for the rest of their life.

Sidra Hafeez   14/01/2019 11:22:53 AM

It is interesting that in Islam, Prophet Muhammad has recommended to fast two days a week.

Wakinyjan Tabart   21/01/2019 11:29:17 AM

YEs, the 5:2 approach can be a life long approach - I have managed to lose weight and keep it off with this approach - what I found is I could lose a couple of kgs easily, then had to maintain that weight for a few months before being able to lose a couple more kgs. Also unless I do at least one day a week I start to regain weight. The other thing I noticed is if I do the 5:2 properly then I tend to have a reduction in craving for unhealthy foods. I probably eat 1000 calories and do about 400 calories extra exercise on the fasting days.