Legumes, soy and plant protein
Soy milk on a GLP-1: protein, portions and how to actually eat it
About 3.3 g of protein per 100 g (3.5 oz), unsweetened, per 100 ml, for around 50 calories. A large glass, about 250 g (8.8 oz), gives roughly 8 g of protein for 125 calories.
How soy milk sits on a GLP-1
Soy milk is the only plant milk that matches dairy milk for protein, at about 3.3 g per 100 ml (3.4 fl oz). Almond, oat, rice and coconut milks sit between 0.5 and 1 g, which makes them a poor swap if you are counting. For someone on a GLP-1 who cannot manage dairy, soy milk is the liquid protein that keeps coffee, porridge and smoothies contributing to the day. It is a little thicker and beanier than milk, and the unsweetened version is the one to buy.
When your appetite is small
Use it wherever you would use milk and add to it the same way. A 250 ml (8.5 fl oz) glass is about 8 g; blended with a scoop of pea or soy protein it is about 30 g and still one glass. In coffee, choose a barista blend, which froths and does not split, so the coffee actually gets drunk.
Three ways to prepare it
As the base of a protein smoothie
Soy milk, a scoop of plant protein, a banana and ice. A complete 30 g stop with no dairy in it.
Warmed with cocoa before bed
A mug of hot soy milk with cocoa and a little honey is about 8 g and settles an unsettled evening.
In porridge, with milk powder or protein stirred through
Oats cooked in soy milk rather than water, with a spoon of soy protein isolate whisked in at the end. About 18 g in a small bowl.
What to eat it with
Coffee, cocoa, oats, banana, and a scoop of plant protein whenever it needs to count. Soy milk with cereal is fine as a habit and short as a protein stop, which is the same problem dairy milk has.
How it compares
| Food | Protein per 100 g | Energy per 100 g | |
|---|---|---|---|
| Soy milk | about 3.3 g | 50 kcal | this page |
| Milk | about 3.5 g | 64 kcal | See the page |
| Kefir | about 3.4 g | 60 kcal | See the page |
| Pea protein | about 75 g | 380 kcal | See the page |
All figures are typical values for the food as eaten, unsweetened, per 100 ml, not laboratory figures for a particular brand.
Australian, US and UK names
Soy milk in Australia and the US, soya milk in the UK. Vitasoy and So Good in Australia, Silk and WestSoy in the US, Alpro and supermarket own brands in the UK. Check the panel: light and flavoured versions can be lower, and some brands are fortified with calcium and B12, which matters if it replaces dairy entirely.
Questions people ask
Which plant milk has the most protein?
Soy, at about 3.3 g per 100 ml (3.4 fl oz), the same as cow's milk. Pea milk, sold as Ripple in the US, matches it. Oat, almond, rice and coconut milks are mostly water and carry under 1 g, so they do not count as protein.
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.