The Role Of Protein And Fibre For Weight Loss

Lots of people are starting a weight loss journey at this time of year. And whilst there’s no single best diet, there are two nutrients that can help you feel full and satisfied, which in turn can make it easier for you to stay on track. 

1 – Protein  

Along with carbohydrates and fats, protein is one of three macronutrients that we need in larger amounts to stay healthy. Your body uses protein for growth, repair and maintenance of its tissues. 

In the U.K. the recommended intake of protein is about 0.75 grams per kilogram of body weight per day. For someone weighing 75 kg (11 stone), that's about 60 grams.

Studies show that on average, most UK adults are meeting this amount, but there are various reasons--such as weight loss--when eating more can be beneficial.

Why is protein helpful for weight loss?

It's generally agreed that protein has a stronger effect on satiety and satiation (how full and satisfied we feel after eating) than the equivalent amount of energy from carbohydrate or fat. Various studies have found that people report less hunger on higher protein diets than lower protein diets. And with less hunger, it's easier to stay on track with your goals.

But there does seem to be a ceiling effect to this - once a certain level of protein has been eaten, there's no extra effect.

This seems to happen when protein makes up around 20% of total calories. So for a 2000 calorie diet, that's about 100 grams of protein. Or if we go back to our person who weighs 75kg, about 1.3 grams of protein per kilo of body weight.

A simple way to approach protein intake

If this all seems a bit complicated, there is a simple approach you can use. For most people on a weight loss journey, aiming to eat 25-30 grams of protein at each meal will be enough to get the appetite benefits.

Most of us eat the majority of our protein intake at dinner, so focusing on higher protein foods at breakfast and lunch is the best place to start.  Several studies have shown that starting the day with a high protein meal (typically 25-30 grams of protein) can reduce cravings later on. 

Animal or protein?

Studies suggest that plant proteins are as effective as animal proteins in terms of satiety, and plant based proteins are a win for the environment too. So, as well as eggs, fish, lean meat and dairy, think about tofu, beans, peas and lentils, nuts and seeds. Many protein-rich plant foods also have the added benefit of being rich in the second helpful nutrient which is...   

2 – Fibre  

Fibre is a type of carbohydrate that we don’t digest or break down. It's found in plant foods - think whole grains (think wholemeal bread, oats and wholegrain pasta), fruits, vegetables, nuts, seeds and pulses (beans, peas and lentils). 

Why is fibre helpful for weight loss?

Fibre is an important nutrient for everyone, but it’s helpful for reaching and maintaining a healthy bodyweight because like protein, it helps us feel full and satisfied after eating. 

Fibre slows down how quickly your stomach empties and triggers the release of hormones that regulate appetite as it moves through the gut. Once fibre gets broken down by your gut microbes, compounds known as short chain fatty acids are released, which also play a role in regulating appetite.  

Beyond a healthy bodyweight, there’s plenty more reasons to eat lots of fibre. Studies have linked high fibre diets with: 

• Supporting a healthy gut environment  
• Stabilising blood sugar levels 
• Reducing the risk of bowel cancer, heart disease, and type 2 diabetes 

 Despite these benefits, 91% of UK adults don’t meet the recommended 30 grams of fibre a day, with average intakes hovering around 18 grams a day. Research shows that meeting the target by choosing

• 5–8 portions of fruit and vegetables a day 
• wholegrains like oats or wholemeal bread two of your main meals
• fibre-rich snacks like nuts and seeds

I'll be sharing more advice on reaching the 30 gram target in the coming weeks, so make sure you're signed up to our newsletter to learn more.

References

Lonnie, M., Hooker, E., Brunstrom, J. M., Corfe, B. M., Green, M. A., Watson, A. W., Williams, E. A., Stevenson, E. J., Penson, S., & Johnstone, A. M. (2018). Protein for life: Review of optimal protein intake, sustainable dietary sources and the effect on appetite in ageing adults. In Nutrients (Vol. 10, Issue 3). MDPI AG. https://doi.org/10.3390/nu10030360 

Raubenheimer, D., & Simpson, S. J. (2023). Protein appetite as an integrator in the obesity system: the protein leverage hypothesis. Philosophical Transactions of the Royal Society B: Biological Sciences, 378(1888). https://doi.org/10.1098/rstb.2022.0212

Gosby, A. K., Conigrave, A. D., Lau, N. S., Iglesias, M. A., Hall, R. M., Jebb, S. A., Brand-Miller, J., Caterson, I. D., Raubenheimer, D., & Simpson, S. J. (2011). Testing protein leverage in lean humans: A randomised controlled experimental study. PLoS ONE, 6(10). https://doi.org/10.1371/journal.pone.0025929

Chambers, L., McCrickerd, K., & Yeomans, M. R. (2015). Optimising foods for satiety. In Trends in Food Science and Technology (Vol. 41, Issue 2, pp. 149–160). Elsevier Ltd. https://doi.org/10.1016/j.tifs.2014.10.007 

Hooper, B., Spiro, A., & Stanner, S. (2015). 30g of fibre a day: An achievable recommendation? Nutrition Bulletin, 40(2), 118–129. https://doi.org/10.1111/nbu.12141