Weight management for optimal health has become a significant issue in many countries. Several medical conditions are greatly improved with weight management to healthier levels : diabetes/prediabetes, dyslipidemia, hypertension, non alcohol related fatty liver disease, obstructive sleep apnoea, osteoarthritis of load bearing joints to name a few of them. As a primary care doctor/GP it is important to keep up to date with the latest evidence for weight control management as there are many misleading claims online and popular fads. Covid pandemic has not helped healthy weight control. Staying at home for months has lead to more eating and drinking for some. I certainly put on weight during 2020 & 2021.
As GPs we believe the science of weight control is simple enough : eat less and exercise more. Perhaps that is too simple a view as it neglects other biological mechanisms such as hunger and how that plays a vital role in maintenance of weight loss. Overfocussing on exercise is also a potential oversimplification. If you have arthritis of the knees and hips for example, its not so simple to do more running. When sociocultural factors promote more eating of more affordable energy dense foods, it is also not so simple to just eat less too.
Management of overweight and obesity in primary care—A systematic overview of international evidence-based guidelines is a 2019 overview of international guidelines on obesity management. A good way to gain an overview of topic for primary care. Importantly it highlights the role of primary care providers .
The Australian Obesity Management Algorithm: A simple tool to guide the management of obesity in primary care is a good start to update yourself on the latest EBM for weight loss and here is its Appendix 4 summarising the our current best EBM knowledge for weight loss interventions. You can see that lifestyle changes alone lead to initial weight loss that is not maintained after 5 yrs. THis is something that I believe we all intuitively understand. Bariatric surgery leads to best long term outcomes. Lifestyle changes and drugs holds the middle ground.
Intervention | Summary of effect |
---|---|
Lifestyle change | > 10% weight loss in few studies; weight loss difficult to maintain for many individuals. Study results:•Dietary change: average weight loss 3–5 kg at 12 months; 0 kg at 5 years•Dietary change and exercise: average weight loss 5–10 kg at 12 months; 0–3 kg at 5 years•Lifestyle change and psychological intervention: average weight loss 3–4 kg at 5 years |
Combined lifestyle change and pharmacotherapy | > 10% weight loss in some but not all studies; weight loss maintained > 2 years in some participants. Study results:•Orlistat and dietary change: average weight loss 6–10 kg at 12 months; 2–3 kg at 5 years [31]•Phentermine and dietary change: average weight loss 6.4 kg 12 weeks [28]•Liraglutide and lifestyle change: average weight loss 8% at 56 weeks [32] and 6% at 3 yr [55]•Naltrexone/bupropion and lifestyle change: average loss 6.1% at 56 weeks [37]•Semaglutide and lifestyle: average weight loss 15% at 68 weeks [42] |
Bariatric surgery with maintained lifestyle changes | > 15% weight loss consistently across studies; weight loss likely to be maintained > 5 years•Laparoscopic adjustable gastric banding: average weight loss 20% at 12 months; 12% at 10 years•Sleeve gastrectomy: average weight loss 25% at 12 months; 16% at 10 years [54]•Roux-en-Y gastric bypass: average weight loss 33% at 12 months; 30% at 10 years [54] |
Medicines for long-term obesity management is another good short EBM review by trusted NPS service into pharmacological management options for weight loss. It doesnt have the latest update which is that Wegovy got TGA approval for weight loss in September 2022
There is no PBS listed medicine for weight loss indication and so cost for private scripts is a major barrier to all of these pharmacological options for weight loss, despite the EBM support for them.
Which then leads us back to lifestyle changes as the only practical intervention for many patients we see in GP land, even though the EBM suggests that is difficult option to maintain long term. The biology of hunger combined with strong sociocultural factors is very difficult to suppress in the long term. However one must balance the long term health effects of all those medical conditions such as diabetes and obstructive sleep apnoea when considering how aggressive an approach should be taken into weight control. It makes little sense subsidising many diabetes medications when supporting weight loss long term by subsidising weight loss pharmacotherapy for induction & maintenance may actually prevent progression or even reverse diabetes. What if as a GP you could reverse someone’s pre-diabetes condition by weight control therapy combined with lifestyle change advice? In the long term would that not be better than watching prediabetes progress to diabetes and then trying to manage the hyperglycemia with more and more diabetes drugs? Isnt being overweight a chronic disease itself?
I have prescribed Phentermine ( Duromine) for weight loss before and longest has been up to 12 months ( its only TGA approved for up to 3 months so longer term prescribing is off label) with a reasonable sustained weight loss effect. The argument here for long term maintenance role of phentermine has been supported with studies overseas of long term phentermine use combined with topiramate as dual appetite suppressants. Cardiovascular safety has been studied. My view is that unhealthy weight is a chronic disease issue and so requires at times long term pharmacotherapy similar to other chronic diseases like hypertension and diabetes. Here are some of the studies in relation to phentermine and topiramate combination for long term weight control. There is no current TGA approval for combining phentermine and topiramate for weight loss so all prescribing for this indication is off label. I have not prescribed this combination yet.As I highlighted cost is a major barrier. Even Duromine is now approximately $120 /month.
Management of obesity and cardiometabolic risk – role of phentermine/extended release topiramate
Long‐term effects of weight‐reducing drugs in people with hypertension
Intermittent fasting is all the rage now with dieting. It is essentially a form of reduced energy intake lifestyle change. What does the EBM show about it? It works. Its about as effective as a low calorie/low energy intake daily diet long term.
Here are 2 articles examining it
Intermittent Fasting and Metabolic Health