Key Takeaways

• Appetite suppressants help to reduce how much a person eats, either by acting in the brain to make them feel less desire to eat, or by acting in the digestive system to help them feel full for longer.

• The most effective appetite suppressants are prescription medications, such as GLP-1 RAs (semaglutide and liraglutide). These are only available with a doctor’s prescription.

• Certain supplements may have an impact on appetite, although the effect is generally small. Many of the supplements marketed as appetite suppressants have not been shown to be effective in high-quality research studies.

• Diet also has an impact on appetite. Protein, healthy fats, fibre, and water all help to keep you feeling full for longer, which will tend to reduce how much you eat.

• When taking an appetite suppressant, there is a risk of nutrient deficiencies. It’s important to focus on eating foods with vitamins, minerals, and protein, and to minimise foods that don’t contain many nutrients, such as processed and sugary foods.

Do appetite suppressants work?

If you’re significantly overweight, then eating less calories will help you to achieve a healthier body weight. However, this can be very challenging for many people. Most people will feel hungry when they reduce their calorie intake. It takes a lot of willpower not to eat when you feel hungry, and it also feels very uncomfortable. Often, this goes beyond willpower, as some people’s bodies are not able to regulate hunger and satiety appropriately.

Because of this, many people are looking for appetite suppressants. By reducing the body’s hunger signals, taking an appetite suppressant could make it far easier and more comfortable for a person to eat less and lose weight. 

There are a number of appetite suppressants currently being marketed. Some of these are only available with a doctor’s prescription, while others can be obtained over the counter. Although some compounds marketed as appetite suppressants are not effective, there are also some that have been proven to be effective and to lead to significant weight loss in most people who take them.

If you’re looking for an appetite suppressant, there are a few things to know about which ones are effective and how you can get access to them.

Prescription Appetite Suppressants

There are a few different prescription medications that work in part by suppressing appetite. The most commonly prescribed type are known as glucagon-like peptide-1 receptor agonists, or GLP-1 RAs. These work by mimicking a natural hormone known as GLP-1. This acts in the brain to prevent you from feeling hungry, and also slows down the emptying of the stomach to help keep you feeling full for longer after you eat.

There are two GLP-1 RAs that are approved for weight loss in Singapore: semaglutide (Wegovy) and liraglutide (Saxenda). Both of these are given by injection, although Saxenda is taken daily while Wegovy is taken once per week.

Clinical trials have shown that people taking Wegovy lose an average of 15% of their body weight over a period of 68 weeks (about a year and three months). In trials of Saxenda, more than two-thirds of patients lose more than 5% of their body weight, and about a third lose more than 10%. Because multiple high-quality research studies have shown that these medications are effective for weight loss, they’ve been approved by the Health Sciences Authority (HSA) for this purpose.

After stopping a GLP-1 RA, it’s common for people to regain much of the weight that they lost. This is not inevitable, and there are effective methods to help maintain weight loss after stopping the medication. However, some people choose to continue taking a GLP-1 RA over the long term, to help them stay at their new, healthier body weight. This is considered to be a safe option, and there have been no major long-term health concerns discovered in people who continue taking these medications.

There are also some other prescription appetite suppressants approved in Singapore.

• Phentermine is a stimulant, meaning that it increases your body’s use of energy. However, it also acts in the brain to suppress appetite. Phentermine has been shown to be effective for weight loss, but it can also cause serious side effects, such as an abnormal heart rate.

• Bupropion-naltrexone contains two different medications, which both act in the brain. They work together to reduce appetite, and also help to control cravings and emotional eating by modulating the brain’s perception of the reward associated with food. They can cause side effects related to mood, as well as other side effects like nausea and high blood pressure.

Semaglutide has been found to lead to greater average weight loss than the other prescription options, and is also considered to be safe for long-term use. For these reasons, it’s likely to be the preferred option for most patients. However, there are very few studies directly comparing these options to each other, so more research is needed to be sure. In addition, individuals have different responses to medications, so it’s important to take a personalized approach to weight loss.

Natural Appetite Suppressants

Some people are looking for a natural alternative to GLP-1 RAs. There are a number of different supplements that are marketed as appetite suppressants. Unfortunately, many of these are not effective. Even when they claim to be “research-based” or “scientifically proven,” this doesn’t mean that they’re truly supported by high-quality scientific studies.

Still, there are a few appetite suppressants that research has shown may be effective, including:

• Glucomannan. This is a type of fibre, which the human digestive system can’t break down. By taking up space in your digestive tract, it helps to keep you feeling full for longer. Some studies have shown that taking glucomannan daily leads to an average weight loss of 3kg over a 12-week period.

• Acacia Fibre (also known as Gum Arabic). This works in a similar way to glucomannan. A few studies have shown that taking acacia fibre daily leads to approximately a 2% reduction in body fat.

• Saffron Extract. This is derived from the flower of the saffron plant. It’s believed to work in the brain to reduce appetite, and it may also help to curb emotional eating. In one study, people taking saffron extract daily lost weight and also had a significant reduction in their snacking frequency.

• Inulin. This is a type of fibre found in a variety of plants, including chicory, asparagus, artichokes, and leeks. In one study, people taking inulin daily lost about 1.5kg more than those taking a placebo over an 18-week period, and they also consumed less food when given an opportunity to eat as much as they wanted.

• Chromium. This is a mineral found in the diet in trace amounts. It’s believed to help improve insulin sensitivity, which is why some people use it as a supplement for diabetes. It’s also believed to act in the brain in ways that can help to reduce appetite and curb emotional eating. Studies have shown that its use can lead to the loss of about 0.5kg of body weight. It’s important for people with diabetes to use caution when taking chromium, as it may increase the risk of hypoglycemia in people taking insulin or other diabetes treatments.

• Green tea extract. This acts as a stimulant, increasing the amount of energy that the body uses. However, certain compounds in green tea are also believed to help suppress appetite. Some studies have shown that taking green tea extract helps people to feel full for longer after eating a meal, although the effect has not been consistent across all studies.

For all of these supplements, while there is some research supporting their use, there are generally only a few small studies that have been done. In some cases, the results of different studies conflict with each other, with some studies showing that the supplement is effective while others don’t. More research is needed to be sure that these appetite suppressants are truly effective.

In general, natural appetite suppressants will have only a small impact on appetite. It’s important to be careful when purchasing a supplement for this purpose, and to have realistic expectations. A natural appetite suppressant may provide a small boost to your weight loss efforts, and it’s something that you could try alongside diet and exercise. However, none of these natural alternatives are nearly as effective as prescription weight loss medications.

Some people prefer natural alternatives because they don’t require a doctor’s prescription. While this does make them more convenient to obtain, it doesn’t necessarily mean that they’re always safe. Supplements can certainly have side effects, and these side effects can be serious in some cases. It’s always better to talk to a doctor about any supplement that you’re considering, especially if you have any medical conditions or take any prescription medications or other supplements. Your doctor can let you know whether the supplement you’re considering would be safe for you.

The most common side effects of appetite suppressant supplements are related to the digestive system, such as constipation, diarrhoea, bloating, indigestion, and nausea. Starting at a lower dose and working your way up may help to reduce these side effects. In general, these side effects will go away after you stop taking the supplement.

Are there foods that help suppress your appetite?

Although there is no one specific food that has been shown to be particularly effective at suppressing appetite, there are certain eating patterns that help you to feel full for longer, so that you end up eating less. If you’re hoping to reduce your appetite, you may want to consider eating more:

• Protein. It takes longer for your body to digest protein than carbohydrates, so it keeps you feeling full for longer. Some foods high in protein include lean meat, eggs, lentils, beans, and tofu.

• Healthful fats. Similarly, fat stays in your digestive tract for longer, so you stay full for longer. Saturated fats, found in sources like red meat and butter, may have negative health impacts. However, unsaturated fats, found in foods like avocados, olive oil, nuts, and seeds, appear to have health benefits and can also help to keep you feeling full.

• Fibre. This is a type of carbohydrate that your body can’t digest, so it stays in your digestive tract and helps keep you feeling full. While some people take fibre in the form of a supplement, there are many healthy foods that are high in fibre, and also contain important vitamins and minerals. High-fibre foods include fruits, vegetables, and whole grains.

• Water. Water helps to take up room in your digestive tract, which may help you to feel full for longer after you eat. Staying hydrated is also important for your overall health. Some studies have shown that drinking a glass of water before a meal causes people to eat less and to feel full for longer after eating.

Our nutritionists can help you to design a healthy eating plan that includes these natural appetite suppressants and also provides you with other important nutrients, like vitamins and minerals. 

Importance of eating adequately while on appetite suppressants

While on appetite suppressants, you will be eating a reduced amount of food overall. However, your body still has the same needs for certain nutrients, such as protein, vitamins, and minerals. You’ll need to make sure that you’re getting enough of these vital nutrients, even though you’re eating less food overall.

This means that, while taking appetite suppressants, it’s crucial to focus on eating healthy, nutritious foods whenever you do eat. You’ll have much less room in your diet for “junk foods” – those that provide calories but contain very few nutrients. Instead, you’ll need to make sure that you’re eating mainly whole fruits and vegetables, whole grains, and healthy protein (from either meat or plant sources, such as lentils, tofu, or beans). 

It can be very helpful to consult a nutritionist to help you plan a diet that will meet your nutritional needs while you’re eating a reduced number of calories. Our NOVI Optimum Plus medical weight loss plan includes support from a nutritionist, so you can create an eating plan that will help to avoid nutritional deficiencies while you’re losing weight.