Judith Johnson B.Sc. Hons.Ther Diet (UCT)
There is no denying we have entered a new era of weight loss management which is rapidly spreading far and wide.
It is not surprizing because successful weight management is very difficult to sustain in our modern world of sedentary lifestyles and poor eating habits. It is often seen as a quick fix but without addressing some of the underlying issues needed especially related to mental health and mood. These medications are easily accessible (although costly) and proving to be successful in not only weight management, but in Diabetes control and in cardiovascular health.
The question is: are there consequences?
What are GLP-1 Medications
Glucagon-like Peptide-1 (GLP-1) receptor agonists are a class of medication used in the symptom relief of obesity, as well as in reducing cardiovascular risk and improved blood glucose control. It is NOT a treatment of underlying obesity, rather a relief of symptoms. These medications were originally used for better diabetes control, but now there are some available specifically targeting weight loss, such as Wegovy, Saxenda, with Mounjaro being a combination therapy drug.
How to they work in the body:
- Slow down gastric emptying, reduces peristalsis in the GI tract
- Slows the release of a hormone glucagon (the body releases this when its blood glucose goes too low, stimulating appetite and food intake)
- Stimulates insulin secretion from the pancreas
- Reduces sugar and salt cravings, reduces appetite
More specifically:
Brain: increases fullness (satiety) signalling, improves motor function, reduces neuroinflammation, reduces memory impairment
Heart: reduces blood lipid levels, improves cardiovascular protection, anti- inflammatory action
Liver: reduces liver glucose production, reduces liver fat content (NAFLD), reduces plasma liver enzyme levels.
Pancreas: increases insulin synthesis and secretions, reduces blood glucose
GI Tract: slows gastric emptying, reduces gastrointestinal peristalsis
Side effects to be aware of:
The most common are nausea, early fullness and an aversion to rich meals. This often subsides as the body adapts to the dose given hence dosage is always started slowly and increased gradually.
Constipation with the reduced gastric emptying, is another common side effect. Numerous studies are now looking at the microbial diversity as essential in preventing this (note: there appears to be a correlation between higher BMI and poorer microbial balance with lower Short Chain Fatty Acid(SCFA) production eg Butyrate.
Muscle wasting can occur if exercise, particular strength training, is not part of the plan. Without a well-planned lifestyle and eating program, muscle loss can be as high as 40% of the total weight lost. This goes down to 11% muscle loss with lifestyle improvements.
Does this matter? Yes, for many reasons. Low muscle mass is associated with higher inflammation. It is also associated with lower energy levels (2) and lower metabolic rate. Muscle wasting in older women (sarcopenia) is associated with less strength, more fractures, increased insulin resistance, and more weight gain and inflammation. This in turn can influence bone density over time, so regular bone density checks are advised. If too much muscle as well as fat volume is lost, this can be noticed as a change in facial features (“Ozempic face”).
Other metabolic complications (loss of appetite, vomiting, diarrhoea, dizziness, infections, headaches, indigestion, pancreatitis, acute kidney injury, allergic reactions, low blood glucose) can occur but are usually related to poor diet, or underlying health conditions, hence it is recommended to have a full health check before deciding with your medical doctor if you are suitable to start these drugs.
Other consequences of long-term use: the uncomfortable truth about GLP1 medications:
Eating is a meaningful, joyous occasion. It is often the centre of social and family time together. We often eat for hedonic pleasure not just hunger. The action of these drugs is to flatten the food desire, and in turn the food noise. If this food noise goes silent, what replaces it? Where does the daily joy/excitement come from? When appetite quietens what happens to pleasure seeking, energy, emotional reward? At higher doses, some experience emotional flattening and increased fatigue. This effect can extend to a more general suppression of the brain’s reward system, impacting experiences of joy outside of eating. This is connected to our dopamine production and hence the need for a lifestyle of activities that can create dopamine such as cold water swimming, exercise, walking on sand and any creative outlet is essential.
This response is not a personal failure; it’s a biological response to how these drugs work.
How long should you take these medications for:
This depends on your weight management goals and how well the drugs are tolerated (physically and mentally). The manufactures advise that you never stop them to prevent rebound weight gain, however is it very important to undergo constant monitoring and to check how your body is coping.
How to stop GLP-1 s safely:
Before stopping, it is important to understand that there can be compensations by the body and some rebound weight gain may occur. There are targeted goals to get right beforehand:
- Establish why you want or need to stop; or is it a temporary cessation
- Taper the drug: either extend the time between injections or lower the dosage or both, but reduce slowly
- Establish the correct food intake goals for yourself
- How much protein to eat, what type is best ( usually lean)
- Check your meals are glycaemic controlled (low GI, unrefined)
- Proper fibre goals are essential as well as enough fibre from polyphenols (colourful plants)
- Ensure diversity of the diet to establish the correct microbiome
- Prioritise sleep hygiene and sleep rhythms
- An activity plan is essential and needs to include strength training more than 1 x week
- Continue metabolic checks such as muscle to fat ratio (In Body Scale)
- Introduce good microbial diversity: a new generation probiotic is now available which mimics the action of GLP1 receptor agonists (Akkermansia muciniphila). AVAILABLE ONLINE https://healthylifecapetown.co.za/product/akkermansia-muciniphila/
To manage weight after cessation:
The human body is equipped with mechanisms of stimulating its own natural GLP1 receptor agonist. The GI tract is a powerful system in the body that when looked after correctly, can often negate the need for medications and makes cessation of the drugs a lot easier. How?
- GLP-1 receptor agonists are formed by the breakdown of certain fibres we eat. They form Short Chain Fatty Acids (SCFA) which convert to GLP-1 receptor agonists.
- Bile acids convert into secondary bile acids, and these also increase GLP-1 receptor agonists.
- Correct dietary fatty acids and glycerol convert to GLP1s (Lipo-Oligosaccharides) hence including good fats is essential.
In summary: This new generation of drugs is proving to be very successful in weight management and in turning down the ‘food noise’. But without the hard work that a correct lifestyle and good eating habits require, success will not be without its consequences. Obesity care remains multifactorial.
References:
- Mehrtash et al: Integrating Diet and physical Activity when prescribing GLP-1 s JAMA Intern Med July 14 2025 PMID: 40658434
- Kim G, Kim JH. Impact of Skeletal Muscle Mass on Metabolic Health. Endocrinol Metab. 2020;35(1):1-6. doi:10.3803/EnM.2020.35.1.1
- Safety and Efficacy of Glucagon-Like Peptide-1 Receptor Agonist in Elderly People with Obesity, A Meta-Analysis: Obesity, 2026:0:1-11
- World Health Organization Guideline on the Use and Indications of Glucagon-Like Peptide-1 Therapies for the Treatment of Obesity in Adults
