Soya Protein Isolate
Soya protein isolate is the core plant protein in every Blue River Diet. It is lean and easily digested, giving geckos the amino acids they need without adding fat.
We are often asked why we chose it over whey, pea or rice protein. This page explains our thinking, and how insect protein fits in alongside it.
Protein at a glance
90%+
Protein content of soya protein isolate
All 10
Blue River flavours include it
18.9–26.2%
Crude protein across the range
15%
Black soldier fly larvae in Fruit & Bug
Range figures from current packaging. Each pouch shows the analysis for its flavour.
On this page
What Is Soya Protein Isolate?
Soya protein comes in several grades. The more the soybean is refined, the higher the protein and the lower the fat and carbohydrate. Isolate is the most refined of the three.
Three grades of soya protein
Soya Flour
Ground, defatted soybeans. Around 50% protein, with much of the carbohydrate and fibre left in.
Soya Protein Concentrate
Some of the carbohydrate removed. Around 65–70% protein.
Soya Protein Isolate
Most of the fat and carbohydrate removed. At least 90% protein, as a fine, easily digested powder.
Typical protein content on a dry weight basis.
Amino Acid Profile
Geckos need the right balance of essential amino acids for growth, breeding and everyday health. Here is how soya isolate compares with the other protein isolates we considered.
Protein comparison
| Amino acid | Soya | Whey | Pea | Rice |
|---|---|---|---|---|
| Histidine | 2.5 | 1.5 | 2.2 | 1.1 |
| Isoleucine | 4.7 | 6.3 | 3.8 | 3.5 |
| Leucine | 7.7 | 10.6 | 6.6 | 6.4 |
| Lysine | 6.4 | 9.6 | 5.9 | 3.8 |
| Methionine + cysteine | 2.6 | 4.9 | 1.6 | 3.2 |
| Phenylalanine + tyrosine | 8.8 | 5.8 | 6.4 | 7.2 |
| Threonine | 3.9 | 6.7 | 3.6 | 3.4 |
| Tryptophan | 1.3 | 1.7 | 0.7 | 0.9 |
| Valine | 4.9 | 5.9 | 4.4 | 4.0 |
What this means
Whey Leads on BCAAs
Whey has more leucine, isoleucine and valine, the branched-chain amino acids valued for muscle building in mammals. Crested geckos are slow-moving, low-exertion animals, so we do not see this as the deciding factor.
Ahead of Pea and Rice
Soya isolate contains more of almost every essential amino acid than pea or rice protein.
Most Phenylalanine and Tyrosine
Soya isolate has the most of the four. Tyrosine is a building block for melanin, the pigment in skin, and for neurotransmitters.
Useful Lysine and Methionine
Both are often in short supply in plant proteins. Lysine is needed to make collagen, and methionine supplies sulphur for keratin in healthy skin and claws.
Insect Protein in Fruit & Bug
Insects are a natural part of a wild crested gecko’s diet, and black soldier fly larvae are a species-appropriate source of protein and amino acids.
That is why Fruit & Bug includes dried black soldier fly larvae at 15% of the recipe. Because the larvae supply so much of the protein, Fruit & Bug contains less soya than our fruit-only flavours, for a mix closer to how geckos eat in the wild.
Keeper note
Fruit & Bug has the highest crude protein of our core range at 22.5%, while still keeping crude fat at 4.8%.
Why We Still Recommend Live Insects
Blue River Diets are complete diets, so your gecko does not need live insects for nutrition. We still recommend offering them regularly for enrichment. Stalking and catching prey keeps geckos mentally stimulated and physically active, which matters just as much as what goes in the bowl.
Gecko Diet guide · Part 3 of 8