Dairy and eggs
Kefir on a GLP-1: protein, portions and how to actually eat it
About 3.4 g of protein per 100 g (3.5 oz), plain, whole milk, per 100 ml, for around 60 calories. A small glass, about 200 g (7.1 oz), gives roughly 7 g of protein for 120 calories.
To reach 30 g of protein from kefir alone you would need about 882 g (31.1 oz). On a small appetite that is often more than one sitting allows, which is why we pair it rather than chase the whole target from one food.
How kefir sits on a GLP-1
Kefir is fermented milk you drink: tangy, slightly fizzy, thinner than yoghurt and thicker than milk. The protein is the same as milk at about 3.4 g per 100 ml (3.4 fl oz), so it is not a protein food in its own right. People on a GLP-1 ask about it because the fermentation makes it easier on the gut for many who find plain milk bloating, and because a small cold sour glass is often tolerable when the thought of eating is not. If gut symptoms are persistent, that belongs with your prescriber, not with a drink.
When your appetite is small
Use it as the liquid in something stronger. A small glass, 200 ml (7 fl oz), blended with a scoop of whey and half a banana is a 30 g stop that is cold, sour and sweet at the same time, and takes two minutes. On its own the same glass is about 7 g, which is a start, not a stop.
Three ways to prepare it
Blended with whey and frozen fruit
Kefir, a scoop of whey and a handful of frozen berries. The sourness cuts the sweetness of the powder, which many people prefer to a milk shake.
Poured over oats overnight
Oats soaked in kefir instead of milk are softer and sharper. Add milk powder or chia for a stronger breakfast.
Plain, cold, in a small glass
Some days a small sour drink is all that goes down. It is about 7 g and it is a gentle start to a day that needs one.
What to eat it with
Berries, banana, honey, oats, cucumber and dill in a savoury version. It is sour, so it suits fruit and sweetness in a way that milk does not.
How it compares
| Food | Protein per 100 g | Energy per 100 g | |
|---|---|---|---|
| Kefir | about 3.4 g | 60 kcal | this page |
| Milk | about 3.5 g | 64 kcal | See the page |
| Greek yoghurt | about 9 g | 95 kcal | See the page |
| Soy milk | about 3.3 g | 50 kcal | See the page |
All figures are typical values for the food as eaten, plain, whole milk, per 100 ml, not laboratory figures for a particular brand.
Australian, US and UK names
Kefir in all three countries, sold in the dairy fridge next to the yoghurt. In Australia it is often from small local dairies, in the UK Biotiful and supermarket own brands are common, and in the US Lifeway is the main brand. Water kefir is a different, dairy free drink with almost no protein.
Questions people ask
Is kefir higher in protein than milk?
No, it is the same at about 3.4 g per 100 ml (3.4 fl oz). What it adds is live cultures and less lactose, which is why some people who find milk bloating do better on it. For protein, blend it with whey or Greek yoghurt.
Your number comes first
Knowing what is in a food only helps once you know how much you are aiming for. The target is 1.2 to 1.6 g of protein per kg of your goal weight, not your current weight, which for most people is 90 to 140 g a day.
Work out your protein targetMore on eating well when your appetite is small: high protein foods for a small appetite, how much protein on a GLP-1, and every food we have written up. The whole system in five documents is the Keep Muscle Kit, A$47 / US$29 / £23.
EverStrong provides nutrition and strength coaching and education. It is not medical advice and does not replace your prescribing doctor.