GLP-1 medications work best inside a plan, not instead of one

GLP-1 medications have changed how we treat obesity. In the STEP-1 trial, adults on semaglutide 2.4 mg weekly lost an average of 14.9% of their body weight over 68 weeks, compared with 2.4% on placebo ^[1]. Tirzepatide (Mounjaro) went further. In the SURMOUNT-1 trial, adults on the highest dose lost an average of 20.9% of their body weight over 72 weeks, compared with 3.1% on placebo ^[2]. Those are results we could not get with medication a few years ago.

There is a detail in that trial that often gets lost. Everyone in it, including the placebo group, also received support with eating and activity ^[1]. The number people quote is the result of a medication plus a program. In my practice I treat these drugs the same way: a strong tool that works best inside a plan, not a replacement for one.

The problem with medication on its own

These medications are now easy to get. Many online programs deliver little more than the prescription, with no real guidance on eating, exercise or what comes next. People lose weight and then find themselves stuck: stay on the medication indefinitely, or watch the weight come back.

The research shows why that worry is real. In the STEP-1 extension, people who had lost an average of 17.3% of their weight on semaglutide regained 11.6 percentage points in the year after stopping, about two thirds of what they had lost ^[3]. In SURMOUNT-4, people who lost 20.9% on tirzepatide and were then switched to placebo regained 14.0% over the following year, while those who continued lost a further 5.5%. Only 16.6% of the placebo group kept at least 80% of their weight loss ^[4].

It is worth being clear about what those trials tested. In STEP-1, the lifestyle program stopped at the same time as the medication ^[3]. In SURMOUNT-4, the switch to placebo was abrupt ^[4]. Neither trial was designed to prepare people to come off the medication. That is a different question and it is the one I build my own program around.

Not all the weight you lose is fat

When weight comes off quickly, some of it is lean mass. Expert consensus guidance from four obesity and nutrition societies looked at the body composition data from STEP-1: of the average 13.6 kg lost, 8.3 kg (62%) was fat and 5.3 kg (38%) was lean mass ^[5]. In a body composition substudy of tirzepatide, about 75% of the weight lost was fat and about 25% was lean mass ^[6].

Lean mass is not all muscle. Muscle itself likely makes up closer to 20% of the weight lost ^[5]. It still matters. Muscle keeps you strong, mobile and metabolically healthy as you age. It is also tied to how long you live. Sarcopenia, the progressive loss of muscle strength and mass, is linked to falls, fractures, physical disability and higher mortality. Obesity makes it worse ^[7]. Losing weight and losing strength at the same time is not the outcome anyone is looking for.

Protect your muscle: protein and strength training

The first step is simply remembering that this matters and building it into the plan from day one. Experts recommend protein of 1.2 to 1.6 g per kg of body weight per day during active weight loss, which for most people works out to roughly 80 to 120 g a day. Intake should not fall below 0.4 to 0.5 g/kg. Long-term intake above 2 g/kg should be avoided ^[5]. If you have kidney disease, your protein target is different, so set it with your clinician.

Exercise matters just as much. Consensus recommendations call for strength training at least three times a week, plus at least 150 minutes of moderate aerobic activity ^[5]. The combination works better than either piece alone. In one randomized trial, people who combined exercise with liraglutide reduced their body fat percentage by 3.9 points over a year, compared with 1.7 points with exercise alone and 1.9 points with the medication alone ^[8].

In practice, that comes down to three habits:

• Eat your protein first at every meal, before the rest of the plate, so it doesn't get crowded out when your appetite is small.
• Strength train at least three days a week, even if it starts with bodyweight exercises or resistance bands.
• Track your strength, not only your weight. A simple measure like grip strength, or how many times you can stand up from a chair in 30 seconds, tells you whether you are keeping your muscle while the scale goes down.

Eating well when you are not very hungry

These medications reduce appetite, which is part of how they work. It also makes it easy to under-eat protein, fluids and nutrients. Expert consensus guidelines recommend smaller, more frequent meals: breakfast, then a small meal every 3 to 4 hours with plenty of fluid. In the first few days, go easy on fatty or high-fibre foods ^[5]. Stay well hydrated. Severe nausea, vomiting or diarrhea can dehydrate you enough to injure the kidneys ^[5].

Micronutrients deserve attention too. Consensus recommendations suggest proactively considering vitamin D, calcium and B12, especially if you are eating less than about 1,200 calories a day for women or 1,800 for men, when deficiencies become more likely. Unusual fatigue or excessive hair loss are warning signs to raise with your clinician ^[5].

Side effects depend on time and dose

I explain GLP-1 side effects to patients as both time dependent and dose dependent. The longer you are on a given dose, the more likely the side effects settle. The higher the dose, the more likely they appear or get stronger. That matches the trials: stomach symptoms like nausea were mostly mild to moderate and happened mainly while the dose was being increased ^{[2, 5]}.

That is why these drugs are started low and increased in steps, usually every four weeks, giving your body time to adjust before the next step. In STEP-1, dose escalation took 16 weeks ^[3]. For semaglutide 2.4 mg, the product monograph steps up from 0.25 mg to the full dose by week 17. If a dose is not tolerated, it suggests delaying the next increase by four weeks ^[9].

My advice is simple. Do not push through symptoms on your own and do not skip ahead. Tell your clinic early, because there is almost always something we can adjust.

Plan for coming off from the first day

Obesity is a chronic condition. For some people, staying on medication long term is the right medical choice. That should be a decision you make with your clinician, not a trap you fall into because nothing else was ever put in place.

So I use the months on medication to build what lasts: protein, strength, regular activity, sleep and a pattern of eating you can keep. When the time comes to taper or stop, those habits are already doing the work. Research on long-term weight maintenance points the same way. In one cohort, about a third of people who lost weight kept at least 75% of it off at five years. Those who did tended to have more physical activity, more emotional support and fewer sugary drinks ^[10]. A meta-analysis of behavioural weight programs also found that improvements in cardiometabolic risk factors largely persisted for at least five years, even when some weight came back ^[11].

What this looks like in a clinic

Doing GLP-1 care well means more than writing the prescription. It means checking in during dose increases, setting protein and strength goals, watching strength and waist size and not only the scale, reviewing labs and deciding together what the long-term plan is, including how and when to come off. Most of that work happens between visits, which is exactly where patients tend to feel on their own.

In my public practice, I rely on patients being referred to publicly funded dietitians. In my private practice, I have a holistic nutritionist on staff. Both work, but neither is easy for most people to get. The support usually stops at the end of the appointment.

How FORME helps

FORME gives each patient a structured program around their medication, approved by their practitioner: protein targets, strength sessions and eating goals broken into weekly steps, the kind of day-to-day guidance a nutritionist and trainer would give, available whenever they need it. The FORME coach follows the clinic's prompts and can answer questions any time, including whether it is time to move to the next dose when the clinic has set that guidance in advance. The care team sees how each patient is doing between visits. The program is built from the start to prepare patients for life after the medication.