What are the top 3 protein sources for fat loss, muscle and gut health?

The question I received: "Juliana, if I want to lose fat without losing muscle — while taking care of my gut, protecting my heart, and reducing my risk of chronic disease — what are the best protein sources to focus on?"

Chicken is fine. So are eggs, cottage cheese, and tofu. But if I had to rank proteins by their overall contribution to long-term health — not just muscle maintenance — three categories consistently pull ahead. They reduce inflammation, feed the gut microbiome, support cardiovascular health, and in the literature they are linked with lower risk of several chronic diseases when they regularly replace more processed protein sources.

Lentils, chickpeas, black beans, kidney beans, white beans, fava beans. Most women I work with eat them once a week, if that. The research suggests three times a week as a minimum — and more if your digestive system handles them well.

What makes legumes exceptional is the combination in a single food: substantial plant protein alongside enormous amounts of fibre, slow-digesting carbohydrates that don't spike blood sugar, iron, magnesium, folate, and potassium — with almost no saturated fat. Unlike most animal proteins, they actively feed beneficial gut bacteria. When those bacteria ferment the fibre, they produce short-chain fatty acids including butyrate, which helps protect the intestinal wall and reduce chronic inflammation. Regular legume consumption is linked to better cholesterol control, improved blood sugar management, and lower risk of cardiovascular disease and certain cancers across multiple large studies (Reynolds et al., The Lancet, 2019; McRae, British Journal of Nutrition, 2018).

For fat loss specifically, legumes are hard to beat: the fibre-protein combination extends satiety and reduces cravings more reliably than most protein bars or shakes.

If legumes cause digestive discomfort, increase portions gradually. Rinse canned versions thoroughly, soak dried legumes before cooking, and maintain good hydration. Your gut microbiome needs several weeks to adapt — give it that time before concluding they don't work for you.

Salmon, sardines, mackerel, herring, trout, anchovies. These are complete, high-quality proteins — but their real advantage is EPA and DHA, the two forms of omega-3 the body uses directly without any conversion step. The evidence is extensive: better cardiovascular outcomes, lower triglycerides, reduced inflammatory signalling, and support for brain and eye function (Calder, Nutrients, 2020). Research also suggests that adequate omega-3 intake, combined with resistance training, may help preserve muscle mass with age — which matters considerably for women over 40 (Phillips et al., AJCN, 2023). Two servings of fatty fish per week is the target most major dietary guidelines align on.

Sardines deserve a specific mention. They sit at the bottom of the food chain and accumulate far less mercury than large predatory fish, while delivering protein, calcium from the bones, vitamin D, B12, and selenium in one affordable can. They are not glamorous. They are extremely effective.

A serving of Greek yogurt typically provides 15 to 20 grams of protein. Its predominant protein is casein — slowly digested, which sustains satiety over hours and supports muscle protein synthesis between meals. It works well at breakfast, as a snack, or after exercise. It also provides calcium, phosphorus, vitamin B12, and depending on the product, live bacterial cultures that may contribute to gut microbiome diversity (ISAPP, 2023–2024).

Choose plain and unsweetened. A flavoured yogurt with 18 grams of added sugar is a different product entirely. Add berries, nuts, or ground seeds to increase the nutritional value further.

Even the best protein sources cannot do their full work in an unbalanced meal. Filling half the plate with vegetables, choosing fibre-rich starches, limiting ultra-processed foods, sleeping enough, and staying active shape the outcome as much as protein selection does. What changes with these three choices is the quality of the foundation — proteins that do more than one job while they're in your body.