Protein supplements
Protein helps maintain good blood glucose levels and is a very important part of a good gestational diabetes diet, therefore many women look for protein supplements to add into the diet to increase the amount of protein being consumed, especially those that follow a plant based diet.
Protein positively affects the growth of fetal tissue, including the brain. It also helps your breast and uterine tissue to grow during pregnancy, and it plays a role in your increasing blood supply.
Pregnancy Nutrition: Food Groups, American Pregnancy Association
Protein supplements are much easier to find these days, with most stores and even petrol stations and coffee shops offering high protein snacks, foods and powders. But are they something that we should be adding into a GD diet and what impact can a high protein supplemented diet have?

The evidence based research on high protein supplementation in pregnancy
Looking into many research studies, high protein supplementation may carry some risks and so it is important to ensure the diet followed is well balanced and not overly high in protein.
From this we cannot say whether high protein supplements are safe to use during pregnancy, especially one which is complicated with diabetes.
It is for this reason that I recommend a REAL FOOD diet which is higher in protein and well balanced using The 8 Golden Rules, rather than a diet which is supplemented with high protein powders and supplements such as protein shakes and bars.
Balanced energy and protein supplementation seems to improve fetal growth, and may reduce the risk of stillbirth and infants born small‐for‐gestational age. High‐protein supplementation does not seem to be beneficial and may be harmful to the fetus. Balanced‐protein supplementation alone had no significant effects on perinatal outcomes.
Antenatal dietary education and supplementation to increase energy and protein intake, June 2015, Cochrane Systematic Review
In two trials (529 women), high‐protein supplementation was associated with a small, non‐significant increase in maternal weight gain but a non‐significant reduction in mean birthweight, a significantly increased risk of SGA birth, and a non‐significantly increased risk of neonatal death. In three trials, involving 966 women, isocaloric protein supplementation was also associated with an increased risk of SGA birth.
Energy and protein intake in pregnancy, October 2003, Cochrane Systematic Review
Protein supplementation during pregnancy has also been debated because there might be competition among amino acids, which might negatively affect fetal growth, as shown in animal models.
In a randomized controlled trial in low-socioeconomic-status pregnant women living in New York, negative pregnancy outcomes (increased risk of infants born small-for-gestational age) were reported with high-protein supplements (providing >34% of energy). But several other studies in which the protein supplements were provided as food and conducted in the presence of adequate energy, showed a significant reduction in the risk of small-for-gestational age infants, suggesting prevention of intrauterine growth restriction. Thus, as discussed extensively by Imdad and Bhutta, protein supplementation during pregnancy must be a balanced protein supplement (<25% of the total energy content) to ensure reduction in risk of small-for-gestational age infants. Furthermore, earlier studies from the Montreal Diet Dispensary found that pregnant women from lower socioeconomic groups who received an intervention with individualized nutritional rehabilitation and consumed ~100 g protein/d had the best pregnancy outcome as measured by reduced incidence of low birth weight.
… protein supplementation during pregnancy should be in the form of food supplements, balanced (within 25% of total energy), and, as stated earlier by Prentice et al., with a view to prevent intrauterine growth restriction and not as a goal to increase birth weight.
The average daily protein intakes would be ~79 g/d (~14% of calories) during early gestation and 108 g/d (~17% of calories) during late gestation for normally nourished women gaining gestational body weight within recommendations.
More studies are also necessary to confirm the positive effect of food-based protein supplements during pregnancy, with a focus on preventing intrauterine growth restriction, to ensure that protein supplements are always as a balanced protein-energy supplement (<25% of total energy content).
Protein and Amino Acid Requirements during Pregnancy, July 2016, American Society for Nutrition
We showed that a moderate protein intake (18–20%E) may support women to consume the largest variety of nutrients across all food groups. However, the findings from Maslova et al. suggest that if this moderate protein intake is made up largely of animal protein it could unfavorably increase offspring BMI in adult life. Antenatal nutritional advice with the aim of moderating energy and optimizing protein intake has been effective in reducing the risk of preterm birth and stillbirth and in increasing head circumference at birth.
High-protein diets during pregnancy: healthful or harmful for offspring?, September 2014, The American Journal of Clinical Nutrition
Protein Bars
Protein bars are something that many find helpful as a snack on a gestational diabetes diet, or some like to use them as a cereal substitute in the mornings served with milk and cream as they can no longer tolerate breakfast cereals.

Many individually sold protein bars contain very high amounts of protein (20-30g per bar) as they are fortified with protein supplements and are aimed at sports enthusiasts who are trying to build muscle etc.
These protein bars can be extremely expensive at a cost of a couple of pounds each, when you could in fact get a more suitable protein bar in a multi-pack that is made from nuts and seeds.
Other protein bars may be labelled as ‘high protein’ when in fact they are not much higher in protein than other snack bars and can actually contain quite high amounts of carbs in the form of syrups, fruits, honey etc. and artificial sweeteners meaning they can contain more sugar than a chocolate bar! Therefore are not a good choice as they will spike blood glucose levels.
Below is a comparison table of widely found protein bars. The ones listed in green are ones which are better ones to try. Amber shows ones that may be tolerable to some and the ones in red you will notice contain much less protein and much more carbs, therefore making them ones to avoid.
Protein (g) | Fat (g) | Carbs (g) | |
TREK Protein Nut Bar Blueberry & Pumpkin Seed 40g | 10.6 | 15.5 | 6.2 |
TREK Protein Nut Bar Coconut & Raspberry 40g | 10.2 | 15.4 | 6.5 |
TREK Protein Nut Bar Chocolate & Sea Salt 40g | 10.3 | 14.9 | 6.9 |
TREK Protein Nut Bar Chocolate & Orange 40g | 10.5 | 14.9 | 7.0 |
Aldi Harvest Morn Protein Bar 30g | 8.1 | 7.1 | 7.4 |
Yes! Tempting Dark Choc, Sea Salt & Almond Nut Bars 35g | 7.1 | 13.3 | 7.5 |
Nature Valley Protein Coconut & Nuts Bar 40g | 10.3 | 12.2 | 8.8 |
Yes! Dark Chocolate, Banana & Pecan Fruit & Nut Snack Bars 35g | 5.8 | 11.3 | 8.8 |
Yes! Sumptuous Cranberry & Dark Choc Nut Bars 35g | 7.1 | 11.9 | 8.9 |
Nature Valley Protein Salted Caramel Nut Bar 40g | 10.3 | 12.3 | 9.4 |
Nature Valley Protein Peanut & Chocolate Bar 40g | 10.2 | 12.0 | 9.6 |
Eat Natural Protein Packed with Peanuts & Chocolate 45g | 10.2 | 13.7 | 14.6 |
Graze Peanut Butter & Chocolate Protein Bites 30g | 4.7 | 8.7 | 12.0 |
Special K Protein Coconut, Cocoa & Cashew Bars 28g | 6.4 | 4.5 | 12.0 |
Special K Protein Blackcurrant & Pumpkin Seed Bars 28g | 6.4 | 4.5 | 13.0 |
ASDA Protein Raisin & Hazelnut Cereal Bars 28g | 4.7 | 4.8 | 13.0 |
ASDA Peanut Butter Fruit & Peanut Bars 35g | 4.2 | 5.8 | 14.0 |
ASDA Cinnamon Apple Fruit & Peanut Bars 35g | 4.1 | 5.7 | 14.0 |
Alpen Protein Bar Chocolate 34g | 6.5 | 3.4 | 15.0 |
ASDA Protein Cocoa & Peanut Cereal Bar 28g | 4.0 | 4.6 | 15.0 |
Cadbury Peanut Protein Brunch Bar 32g | 4.7 | 7.8 | 16.0 |
Alpen Protein Bar Berries & Yogurt 34g | 6.5 | 2.5 | 16.0 |
Trek Cocoa Oat Protein Flapjack Bar 40g | 7.4 | 8.8 | 17.6 |
Cadbury’s Brunch Cranberry & Nut Protein Bar 32g | 4.4 | 6.1 | 18.0 |
Nairn’s Gluten Free Oat Bar Mixed Seeds & Protein 40g | 5.4 | 7.4 | 18.9 |
Nature Valley Nut Butter Peanut Biscuits 38g | 4.4 | 10.5 | 19.7 |
Nature Valley Crunchy Peanut Butter Cereal Bar 42g | 4.3 | 9.0 | 25.1 |
Nature Valley Crunchy Oats & Dark Chocolate Cereal Bar 42g | 3.7 | 8.4 | 25.2 |
Nature Valley Crunchy Oats & Honey Cereal Bar 42g | 3.4 | 7.2 | 27.1 |
Nature Valley Crunchy Canadian Maple Syrup Cereal Bar 42g | 3.3 | 7.2 | 27.1 |
Don’t think of a protein bar as a source of protein alone
With the protein bars listed above in green and amber, these should not be considered as a protein source alone as many still contain the equivalent of around 2 tsp of sugar. Therefore it is best to always pair protein bars with natural fats.

Protein rich, lower carb foods
Here is a list of protein rich foods which are lower in carbohydrates that could be incorporated into a GD diet instead of using protein supplements.
There are other foods which contain good amounts of protein such as beans, pulses, lentils and oats etc. however these sources of protein are higher in carbohydrates and so need to be thought of as a carb on the plate.
- Eggs (one medium egg contains around 6g of protein)
- Milk (200ml of whole milk contains around 7g of protein)
- Greek Yogurt (100g serving contains around 9g of protein)
- Cottage cheese (100g serving contains around 9g of protein)
- Cheddar (50g serving contains around 12g of protein)
- Babybel cheese (1 mini Babybel contains 4.5g of protein)
- Salmon fillet (100g of salmon contains around 25g of protein)
- Tuna ( ½ of a can ~ 50g contains around 13g of protein)
- Cod (100g serving contains around 16g of protein)
- Prawns (100g serving contains around 13g of protein)
- Chicken breast (150g breast fillet contains around 36g of protein)
- Turkey (100g serving contains around 30g of protein)
- Beef, Pork, Lamb (100g serving contains around 20g of protein)
- Tofu (100g serving contains around 12g protein)
- Soya Milk (200ml contains around 10g of protein)
- Soya Yogurt (100g serving contains around 4g of protein)
- Edamame beans (50g serving contains around 6g of protein)
- Broccoli & Cauliflower (100g serving contains around 4g of protein)
- Brussels Sprouts (100g serving contains around 3.5g of protein)
- Nuts & seeds (25g serving contains around 6g of protein)
- Peanut butter (30g spoonful contains around 8g of protein)
