Fact or fad? Protein: all you need to know

DL dietitian and diabetes educator Dr Kata Marsh weighs in on the high-protein craze

Diets rich in protein are all the rage right now with an ever-expanding range of shakes, powders, balls and bars to help you boost your intake. But what is protein exactly, what does it do in your body, and do you really need to be aiming to eat more of it?

Why we need protein

Protein is a part of every cell in your body and you need it to build and repair tissues and make enzymes and hormones. It’s also important for growth and development in children and teens, and during pregnancy.

While it’s a diet essential, you need less than you might think. In fact, the latest national dietary survey found that almost all Australians (99 per cent!) are meeting their protein needs based on the Estimated Average Requirement (EAR), which is the minimum amount needed for normal growth and repair.

Men aged 19 to 70 need 0.84g and women need 0.75g per kilogram of body weight. So, a man weighing 90kg would

need around 75g of protein and a woman weighing 70kg would need around 53g protein per day, which isn’t hard to achieve.

If you ate, for example, half a cup of muesli with 100g Greek yoghurt and berries for breakfast, a wholegrain sandwich with 100g tuna and salad for lunch, a chicken and vegetable stir-fry with rice for dinner, and a handful of almonds along with a latte for snacks, you would have consumed more than 80g of protein during the day.

As we age, we need a little more. Men aged 70 and above need 1.07g and women need 0.94g per kilogram of body weight.

Is high protein/low carb the way to go?

If you’re watching your weight and blood glucose levels (BGLs), you’d be forgiven for thinking you needed to replace carbs with protein. After all, protein doesn’t have the same immediate impact on BGLs as carbs do, and including a little more protein in your diet can help with satiety.

But research is divided when it comes to the benefits of highprotein, low-carb diets, particularly as there’s a lack of long-term evidence. A 2012 review of 74 studies concluded that, while higher-protein diets probably lead to improvements in weight loss and reductions in waist circumference compared to lower-protein diets, the actual differences are small.

A second review of 15 long-term studies (at least 12 months in length) concluded that highprotein diets are neither beneficial nor detrimental when it comes to weight management, heart disease and blood glucose control, and that there isn’t currently enough evidence to recommend them. It’s all rather confusing.

Too much of a good thing?

While protein is important, there’s evidence to show that eating too much isn’t good. In one study, adults aged between 50 and 65 who ate more protein had a 75 per cent increase in overall mortality and were four times more likely to develop cancer. Several studies have now shown that higher intakes of red meat and processed meats, typical of many high-protein diets, are linked with a higher risk of type 2 diabetes, heart disease, bowel cancer and overall mortality.

Plant protein doesn’t seem to carry the same risks as protein from animal foods, so be mindful not to make it all about meat. Instead, incorporate more plant proteins such as legumes and tofu that are easy to cook and have other health benefits (See page 55 for some easy meal ideas).

Too much protein can have an adverse effect on kidney function, which is a common underlying factor for people with diabetes, so the key is to find a healthy balance that works for you. n