Millions of people in the UK and beyond have turned to drugs like Ozempic and Wegovy to shed pounds. These medications cut hunger and help drop weight fast. But experts say many users end up losing muscle and missing key nutrients because they get little advice on what to eat.
Background
Ozempic and Wegovy contain semaglutide, a drug that copies a hormone called GLP-1. This hormone tells the body it is full after meals. The drugs make people feel less hungry, eat smaller amounts, and lose weight. They can cut daily calorie intake by 16 to 39 percent. Tirzepatide, sold as Mounjaro, works in a similar way.
These drugs have changed how doctors treat obesity. In the UK, about 1.5 million people use GLP-1 drugs like these. Most, around 95 percent, buy them from private clinics. National rules say they should pair the drugs with lower calorie diets and exercise for those with a BMI over 35 and health issues like diabetes or heart problems.
Doctors first approved these for diabetes control. Now they prescribe them for weight loss too. Sales have boomed as more people seek quick results. But the rush has left gaps in care. Few get steady help on food choices while their appetite drops sharply.
Researchers at University College London and the University of Cambridge looked into this. They reviewed studies on nutrition for people on these drugs. They found just 12 papers that touched on diet advice with semaglutide or tirzepatide. Those studies varied a lot in methods. None gave clear rules on best practices.
Key Details
The main worry is muscle loss. When people eat less, they can lose up to 40 percent of their weight as lean mass, mostly muscle. This weakens the body, raises fall risks, and slows daily tasks. Low protein intake makes it worse. Muscle helps burn calories and keeps bones strong.
Nutrient Shortfalls
Users often skip vitamins, minerals, fiber, and protein. This leads to tiredness, weak immunity, hair fall, and bone thinning over time. The drugs curb overall food but do not guide toward healthy picks. Some eat too much fat instead of balanced meals.
Experts point to lessons from weight loss surgery like gastric bands. Those patients get strict diet plans with high protein spread over meals. They focus on nutrient-packed foods to hold onto muscle during fast weight drop. The same could help drug users.
Small, frequent meals might ease side effects like nausea early on. But trials rarely test meal timing or fat limits. One look at real users found high saturated fat intake, which clogs arteries.
"Without appropriate nutritional guidance and support from healthcare professionals, there is a real risk that reduced food intake could compromise dietary quality, meaning people may not get enough protein, fibre, vitamins, and minerals essential for maintaining overall health." – Dr. Adrian Brown, UCL Centre of Obesity Research
Private providers often skip this advice. Public health services push full programs, but access stays limited. Users need plans tailored to their drop in hunger.
What This Means
For users, poor nutrition trades obesity risks for new ones. Muscle loss hits strength and raises injury odds. Nutrient gaps weaken the body long-term. Weight comes back fast if drugs stop, often quicker than from diet alone. Heart and diabetes gains fade in under two years.
Doctors must weave in diet help from the start. This means checks on protein goals, like 1.2 to 1.6 grams per kilogram of body weight daily. Spread it over meals: eggs, fish, yogurt, beans. Add veggies, fruits, and whole grains for vitamins.
Clinics could copy surgery protocols. Track body makeup with scans to watch muscle. Teach on side effects like gut slowdown, which ties to belly pain or vomiting.
Researchers call for more studies with user input. They want standard ways to measure diet quality and patient views. A new project, AMPLIFY, aims to fill these holes.
Patients should ask providers for meal plans. Track intake with apps. Strength training twice weekly builds muscle. See a dietitian if possible.
Broad use of these drugs grows. In 2026, more people start them. Without fixes, health systems face higher costs from fallout like falls or bone breaks. Steady support turns weight loss into lasting health gains.
Experts stress drugs work best with lifestyle changes. Eat smart, move more, get guidance. This keeps benefits without the downsides.
