Key points:

• High in protein relative to animal meat.
• High in essential amino acids Lysine, and muscle building leucine, isoleucine and valine.
• High in essential minerals, except calcium.
• Low in essential amino acids Tryptophan and Methionine.
• Proportionally higher in fat than animal meats, with a similar fat make up.
• A source of dietary fibre.
• Low in carbohydrates.

Mealworms are more nutritious compared to beef, and very similar in nutrition to soybean. This article will look at the macro- and micro- nutritional breakdown of mealworms. Mealworms are a great animal feed and human food due to their high protein content and sustainability, to learn more check out our other blogs insects the future.

Exact percentages are hard to obtain as they depend on many factors, but according to Mariod (2020):

Live mealworms are:

• 62% moisture
• 20% protein
• 13% fat
• 2% fibre

Just like humans, mealworms are mostly made of water, so their nutritional breakdown is weighted to moisture content. Drying the insect allows us to analyse it better. 

Dried mealworms are:

• 6% fibre, a nutrient not found in meat. 
• 28% fat, which is higher than animal meat, but is mostly unsaturated fat which is healthier than the saturated fats in red meat. 
• 53% protein, similar to chicken and more than beef.

 

Mealworm protein is high in essential amino acids Lysine and Leucine but low in Tryptophan. Amino acids are compounds that the body needs to function properly, and essential amino acids are ones that the body can’t make and must be obtained from the diet.Mealworms also contain many B-vitamins and essential minerals like magnesium, phosphorus, potassium, sodium and zinc. 

For a more detailed breakdown and explanation of the micro-nutrients of mealworms, read more below:

1. Protein and Amino acids

Protein content of insects is generally higher than animal meat, relative to weight. Nutrient content depends on the diet but, on average, an equal amount of mealworms and beef would (on average) have similar amounts of protein. Breaking down protein into amino acids shows Lysine is the most common essential amino acid present. It’s used in the body to make proteins and enables the uptake of essential minerals. Most cereal grains are lysine deficient and livestock farmers need to use additives, which makes mealworms a perfect alternative feed.Mealworms are relatively high in the ‘branched-chain amino acids’ leucine, isoleucine and valine which are important essential amino acids for muscle development. 

Mealworms are lacking in methionine and cysteine, which are both sulphur-containing amino acids, and very low in tryptophan. Methionine is used in the growth of new blood vessels and can be found in greater quantities in eggs, nuts and seeds. Tryptophan is used to make serotonin and vitamin B3 and can be found in poultry. The complete amino acid profile can be found below:

Amino acid concentration (g/kg dry)	Tenebrio molitor   (M. De Marco et al., 2015)
Essential amino acids
Histidine	16.8
Isoleucine	22.1
Leucine	31.5
Lysine	35.9
Methionine	10.1
Phenylalanine	18.8
Threonine	18.5
Tryptophan	1.50
Valine	28.2
Dispensable amino acids
Alanine	38.9
Aspartic acid	43.7
Arginine	28.0
Cysteine	12.5
Glycine	22.1
Glutamic acid	62.9
Proline	34.3
Serine	22.7
Tyrosine	32.8

 

2. Fat

Mealworms are high in fat in proportion to other animal meats, so for the same amount of each product mealworms would have more fat. This leads insect meal manufacturers to remove fats and oil before making animal feed. The fat is mostly made up of essential fats Omega-6 and Omega-9, which are unsaturated and less likely to cause damage to the body. Much like animal meat, omega-3 content is low and should be obtained from nuts and fish.

 

3. Vitamins and Minerals

Mealworms contain good amounts of B-vitamins, though have less thiamin and B12 than other insects. They also have some vitamin C content. They don’t have much vitamins A, D or K.  Mealworms contain essential minerals like magnesium, zinc, iron, copper and manganese.

Iron carries oxygen to the cells in the blood, magnesium is used for respiration and bone building. Zinc, copper and manganese are all essential nutrients for enzyme production A common problem when feeding insects to poultry and reptiles is calcium deficiency, which requires a calcium supplementation. Calcium is low in mealworms but is found in dairy and leafy greens like spinach. Mealworms contain chitin, which not only is a source of fibre but has been shown in studies to have immunity-enhancing effects in chicken diets. It reduced the growth of disease spreading bacteria like E. coli, while promoting good bacteria like Lactobacillus.

 

How do mealworms compare to Beef?

Beef fat contains more saturated fats than mealworms. Saturated fats become solid in blood vessels and cause blockages and raise cholesterol levels, which is why nutritionists tell you to eat less red and processed meat. While beef has a higher protein content, mealworms have a higher content of tyrosine, used to make brain chemicals, and alanine, used to make proteins, plus essential muscle developing branched-chain amino acids isoleucine, leucine and valine.

They contain comparable values of calcium, copper, sodium, potassium, zinc and selenium. Beef has more iron. Mealworms have better vitamin content, containing vitamin C which is not found in meat. The only vitamin found in higher quantities in Beef is vitamin B12. As said earlier, insects contain fibre, a nutritional element that meat is completely lacking in. Fibre is used to keep the digestive system healthy and is associated with reducing heart disease and diabetes

 

How do mealworms compare to Soybeans?

The two meat alternatives are similar in many ways: Soy has a 50% dry protein content and is similarly high in fat. While soy is much higher in the amino acids that are lacking in mealworms (methionine and tryptophan), it still needs methionine supplementation from other food. Soy has carbohydrates, which mealworms do not contain. Soy is a better source of molybdenum and while it contains more manganese, it’s in a form the body finds hard to absorb.