Foods That Make GLP-1 Side Effects Worse

Almost nothing is banned. Some things are expensive.

There is no list of forbidden foods on a GLP-1, and anyone selling you one is guessing. What exists is a short list of things that reliably make the side effects worse, roughly in order of how much difference they make. Treat this as a list of what to spend your very limited stomach space on, not as a diet.

In order of impact

1. Portion size. The most common trigger is not a food, it is the amount of it. A meal that would have been modest before the drug is a large meal now. Halving the portion fixes more nausea than eliminating any ingredient.

2. Fried and heavily fatty meals. Fat slows stomach emptying more than anything else you can eat, and the drug has already slowed it. This is why a takeaway sits like a stone, and why the same fish, poached rather than battered, does not. Grill, poach, bake, and keep creamy sauces small.

3. Eating late. Food that is still in your stomach when you lie down is food that comes back up your oesophagus. Two to three hours between the last meal and bed removes most reflux complaints without changing what you eat.

4. Alcohol. Empty calories in a stomach that has no room, worsened reflux and nausea, and, if you also take insulin or a sulfonylurea, a real risk of low blood sugar. Many people find they simply want it less. If you drink, discuss it with your prescriber rather than assuming it is fine.

5. Fizzy drinks. Gas added to a stomach that is already slow to clear. They also displace fluid you would otherwise be getting usefully.

6. Sugar alcohols. Sorbitol, maltitol and xylitol, in sugar-free sweets, gum and a lot of protein bars, are a common and completely unsuspected cause of diarrhoea and bloating. If your gut is unhappy and you cannot work out why, check labels here first.

7. Very sweet and very spicy foods. More variable between people, but both are frequent triggers for nausea and reflux. Worth testing on yourself rather than assuming.

What to swap in

| Instead of | Try | Why | | --- | --- | --- | | Fried chicken, battered fish | Grilled chicken, poached cod, prawns | Same protein, a fraction of the fat load | | A large single dinner | Four to six small feeds | Fits a slow stomach instead of fighting it | | Creamy or oily sauces | Tomato, stock or yoghurt-based sauces | Keeps food moist without the fat | | Fizzy drinks, squash | Water, milk, tea, thin soups | Fluid that also counts towards hydration | | Sugar-free sweets and bars | Greek yoghurt, a handful of nuts | Protein instead of sugar alcohols | | Raw salad mountains | Cooked, soft vegetables and pulses | Fibre that is easier on a slow gut |

One thing to be careful about

The list above is about tolerance, not virtue. On these drugs it is easy to drift into eating almost nothing because everything feels like a risk, and under-eating is the more common failure here than over-eating. If the set of foods you feel safe with is shrinking week by week, that is a reason to talk to your prescriber or a dietitian, not a reason to shrink it further.

Work out what you should be aiming for with the TDEE calculator and the macro calculator, and use what to eat on a GLP-1 for the foods that do the most work in the least space.