“I honestly thought, now I’ll finally lose weight without having to make an effort. Inject, weight down, done. I’d written off exercise. That I was doing exactly the wrong thing with that simply wasn’t clear to me. A body composition analysis had to show me first.”

Andreas is 46 and has been in field sales for over fifteen years. His working day largely plays out in the car: out in the morning, three or four appointments across the region, a coffee at the petrol station in between, a schnitzel with the client at midday, often a business dinner in the evening. Movement barely features in this day, and eating follows the appointment, not the hunger.

For a long time this was not an issue for him. The weight came slowly, a few kilos a year, nothing that stands out on a single day. Only when the trousers no longer did up and the stairs to the office suddenly became a topic did he start to think about it. It got really serious at a routine check-up, when his doctor went through the blood values.

The diagnosis was prediabetes. A preliminary stage, not diabetes, but a clear warning signal. His doctor talked with him about the options and, after their joint conversation, prescribed a weight-loss injection with the active ingredient tirzepatide and regular follow-up appointments. For Andreas this felt at first like a simple, elegant solution.

“The injection sounded outstandingly simple to me. My day is scheduled to the minute. I sit in the car, I sit with the client, I sit at meals. In my head there was never room for exercise, and honestly no desire either.”

The thinking error: losing weight without effort

The first weeks went exactly as Andreas had imagined. The appetite noticeably declined, the large portions at business dinners got smaller without him having to force himself. The weight went down, without the struggle he knew from earlier, half-hearted attempts. He was satisfied and saw his assumption confirmed: “I don’t need exercise.”

That was precisely the thinking error. A weight-loss injection with active ingredients like tirzepatide mimics a gut hormone produced by the body, dampens the appetite and slows gastric emptying. It changes how much someone eats. But it does not decide what the lost weight consists of. Anyone who does nothing for their muscles in the process loses a considerable part of it from exactly this substance.

After a few weeks Andreas noticed that something was not right for him. The weight was down, but he felt weak. Stairs that had been strenuous before did not feel lighter now, but shaky. In the mirror his face looked sunken, almost as if he were ill. The strength with which he had once effortlessly lifted the crate of drinks into the boot had simply become less.

“I was lighter, but I didn’t feel fitter. Rather the opposite. A tired, strengthless version of me. I put it down to the adjustment and didn’t think any more of it.”

The turning point on the scale at the doctor’s

What tipped the balance was a follow-up appointment. His doctor did a body composition analysis, which measures not only the weight but also the composition. The result was sobering: a large part of what Andreas had lost was not fat, but muscle mass. Exactly the substance he would have needed most urgently for strength, metabolism and everyday fitness.

His doctor explained to him that this is not an isolated case but a known pattern with this type of therapy. And that the injection does open the window, because it reduces eating, but that he himself is responsible for what happens in this window. Without a stimulus for the muscles, the body breaks them down too in a deficit.

Fifty Five Insight: In registration trials (including STEP-1, SURMOUNT-1), summarised in a review (Neeland et al. 2024), roughly 25 to 40% of the weight lost under GLP-1 active ingredients comes from fat-free mass (including muscle). The reason: the injection lowers energy intake and thus often protein intake too, and in a deficit the body also draws on muscle protein. The most effective counterpart is considered to be strength training in combination with adequate protein. Protein alone, without a training stimulus, is not enough for this. We go deeper in our article on muscle loss and muscle preservation.

“When the doctor showed me the numbers, the penny dropped. I’m losing weight, but I’m also breaking myself down right now. That was a different picture from the one I’d had in my head.”

From couch type to three times a week

Andreas changed his whole life on the back of this. At first reluctantly, and not entirely voluntarily. For decades, strength training was to him something for other people, not for a field sales rep with a full calendar. His doctor and a personal trainer at the gym convinced him to start with a targeted full-body programme: three times a week, a few basic exercises, no heroics. What this can look like in detail is described in our article on strength training on the weight-loss injection.

“I’d always thought strength training was vanity. Today I know that it’s what keeps my strength in everyday life. I don’t train for the mirror, I train so I can lift the crate of drinks again.”

What surprised him: after a few weeks came a drive he had not counted on. Not because the training was suddenly fun, but because for the first time he had the feeling of having something in his own hands. The injection ran in the background, but the strength that slowly came back he had earned himself. In parallel, he watched his protein more consciously, spread across the day, even on the road.

The third area was for him the most inconspicuous, but the hardest in everyday life: a stable basic supply. When the appetite is dampened and the food comes from the petrol station and restaurant anyway, the diet quickly becomes one-sided. This is exactly where, under a medically supervised therapy, a supply gap can arise that has nothing to do with the injection itself, but simply with the fact that less and less varied food is eaten.

A base that comes along on the road

For the basic supply, Andreas decided on BASE by Fifty Five, a multivitamin and mineral complex that above all had to do one thing for him: simply work in a day scheduled to the minute. A broad base that he takes in the morning without having to think about what ends up on the plate that day. BASE covers, among other things, B12 and thiamin, two nutrients that contribute to a normal energy-yielding metabolism.

On top of that came CALM by Fifty Five, our magnesium complex, which he takes in the evening after training. Magnesium contributes to normal muscle function and to a reduction of tiredness and fatigue. For Andreas, who is right in the transition phase and is putting strain on his muscles again after years, this is an understandable building block in the evening ritual, not a miracle cure. Magnesium is also one of the nutrients that become scarce more often under a weight-loss injection.

What mattered was that his doctor made one more fundamental thing clear to him: the food supplements are not an enhancement of the injection. They secure the basic supply of important nutrients alongside the medically supervised therapy. Which nutrients typically become scarce under a weight-loss injection we have compiled in the large weight-loss injection guide.

“I don’t have the feeling that anything is pumping me up. It’s more that the base is right and I don’t have to worry about that stuff. One less thing that gets lost in the car-appointment-meal chaos.”

Andreas’ conclusion: the injection opens the window, the work he does himself

Andreas today is lighter and, what matters more to him, stronger than at the start of the therapy. The sunken face is gone, the strength in everyday life is back. He would not claim that everything is easy. The training still takes an effort of will, and the full calendar stays full. But he has understood that the injection only does part of the work.

The real difference for him lies in the attitude: the weight-loss injection opens the window by reducing eating. What he builds up in this window he decides himself, with the dumbbell in his hand and a nutrient supply that comes along. His therapy continues to be medically supervised, and this time he will look at the body composition analysis at the next appointment without worry.

“At the start, losing weight was something that happened to me. Now it’s something I actively shape myself. That’s the whole difference.”

Disclaimer:

This article is for informational purposes only and does not replace medical advice, diagnosis, or treatment by a physician or pharmacist. The information provided here should not be used for self-diagnosis or self-treatment. Food supplements are no substitute for a balanced, varied diet and a healthy lifestyle. For any health questions or complaints, please always consult a doctor you trust. Fifty Five accepts no liability for any inconvenience or harm resulting from the use of the information presented here.