High protein = high risk

2 mins to read

Have you been tempted to try a high protein diet? According to online personal trainer Andrew Cate, any potential weight loss benefits should be weighed up against potential health risks.

Weight management

Protein and weight loss

Protein is an important nutrient for weight control. The building blocks of protein (amino acids) are complex, making protein a difficult nutrient to break down. It takes considerably more kilojoules to digest and metabolis protein compared to carbohydrates or fat, and this helps elevate your metabolism.

Protein-rich foods also have a big impact on suppressing hunger and satisfying your appetite. This can help you feel fuller for less kilojoules which is crucial in controlling your weight. In addition, protein helps preserve lean muscle mass when your kilojoule intake is reduced.

Eating the right amount of protein is a much-debated topic. High protein diets have gone through a phase of popularity and celebrity endorsements, yet where some is good, more isn’t necessarily better. Research is beginning to show there may be some health risks associated with a high protein diet.

The research

A recent study compared a moderate protein diet with a high protein diet for both weight loss and changes in bone mineral density. Both groups reduced their kilojoule intake by 3150 kilojoules (750 calories) a day.

The moderate protein diet contained 18% of kilojoules from protein from vegetarian, dairy and egg sources, while the high protein diet contained 30% of kilojoules from protein, with that coming from a combination of animal (lean pork) vegetarian, dairy and egg sources.

Both groups lost approximately 8.5 kilograms over the 12 week study, but those who ate the higher-protein, meat-containing diet lost bone mineral density. This bone loss occurred even though dietary calcium intake was high (2000 mg/day).

According to the researchers, one suggested mechanism is that animal protein increases urinary calcium excretion. This study also suggests that focusing on a lower kilojoule diet with a moderate protein intake from non-meat sources can still result in significant weight loss.

Another study has suggested that a higher intake of vegetable protein, but not animal protein, is associated with an improved heart health risk. This was thought to be due, in part, to an increased intake of unsaturated fats, dietary fibre and micronutrients including vitamins, minerals and phytochemicals.

Getting the balance right

While protein is an important nutrient for energy and weight loss, it’s also important for your health not to eat too much of it. The following tips offer a guide to how to get the balance right.

The recommended dietary allowance for protein is 0.16 grams per kilogram of body weight per day
Try to vary your protein intake by including plenty of plant sources such as tofu, soy drinks, and pulses (beans, peas and lentils)
Eggs are a good source of protein. Just focus on healthy cooking methods such as poaching and hard boiling, and limit the fatty accompaniments that often come with eggs, such as bacon, sausages and hollandaise sauce.
Include a little protein with every meal, but manage your portion sizes. For example, it’s recommended that a good serving size for meat matches the size of the palm of your hand.
Choose lean varieties of animal based protein sources to minimize your saturated fat intake. For example, eat chicken without the skin, trim the fat from red meat and avoid battered foods.
While dairy products are a good source of protein, choose the low fat varieties such as skim milk, cottage cheese and low fat yoghurt.
Fish and seafood are rich sources of protein. Try to eat fish and other seafood (prepared using healthy cooking methods) 2 – 3 times a week.
There’s no need to rely on protein bars, powders and supplements unless you struggle to get an adequate amount of protein through a normal diet.

References available on request