10 weird signs you're eating too much protein

Take a diet check with the help of our articles, How to add enough fibre to your diet, 5 reasons protein is good for your health and 10 nourishing recipes to pack in 30 plant foods.

We all need protein to function. It's one of three essential macronutrients, along with carbs and fats, that our bodies need for growth, repair and our immune system.

Listen to fitness influencers and personal trainers, though, and you may get caught up in the hype around supplementing with protein powders and snacks before hitting the gym, or feel encouraged to follow high-protein, low-carb diets to lose weight fast.

Research shows that there’s some truth in both these claims but they can lead us into consuming far more protein than is necessary or even healthy. Protein helps with weight loss as it quells our hunger hormone, ghrelin, and so keeps us feeling fuller for longer. We burn more calories when we eat protein – it gives us a 20-30% calorie burning lift, compared to 5-10% for carbs and 0.3% for fats. However, following a high-protein, low-carb diet for too long can have some unappealing and unhealthy consequences (see below).

It’s also true that protein-rich foods help repair muscle damaged after intense exercise and training, and help build new muscle. But do we need supplements to achieve this? Specialist dietitian and life coach Tracy Kelly thinks not. She says there is a certain obsession with protein powders and protein-rich snacks such as chocolate bars, which comes down to convenience mostly and at the expense of fibre-rich plant foods. "Protein powders have a place but they should complement, not replace real food," she says.

It’s a different story for elite athletes who need far more calories and protein compared to someone spending an hour at the gym or doing a 5k Parkrun. For example, a top tennis player may eat 3,500-5,000 calories a day, with carbs for energy and protein for muscle building and repair after a game. Protein is increasingly seen as key for recovery between matches so players can get back on court in the best shape.

Most of us easily meet the recommended daily protein intakes of 45g for women and 56g for men. The British Nutrition Foundation surveys estimate that men already consume around 85g and women about 67g protein a day in the UK.

UK guidelines for protein intake are set at 0.75g of protein per kilogram of body weight. That is for sedentary people and most of us will need more. The US Department of Agriculture has a useful calculator for working out your protein needs based on your height, weight, age and activity levels.

"The more active you are, the more protein you need," says Tracy. The extra protein helps repair and rebuild muscle cells that are damaged during exercise. "Active people need between 1.2-2g of protein per kg body weight. This range is influenced by many factors such as age, level of activity, health, current goal and so on," she says. "This means a 70kg person should eat around 84-140g protein per day. Going above the recommendation isn't always a smart move – it's about balance," says Tracy.

Protein portion ideas

What’s important is to get protein from a range of different foods, including beans, lentils and chickpeas that are naturally low in fat and high in fibre. Women should be eating two portions a day and men three. Here are some ideas to get you started:

• Two eggs – a complete protein with all the nine amino acids that the body can’t produce
• 200g beans or chickpeas, storecupboard saviours that contain protein and carbohydrates, and are ideal for including in meals after exercising
• One handful of nuts (preferably unsalted) – contain healthy fats and protein, and are good for bulking out porridge with extra protein
• A palm-sized portion of tofu – another complete source of protein that provides all nine essential amino acids our bodies need for growth, repair and immunity

10 symptoms of too much protein

Consuming too much protein, as high as 2.5g of protein per kg of body weight, can put you at risk of the following:

1. Gym farts Too much protein powder in one go can cause some digestive issues such as bloating and gas, says Tracy. The term was coined by body builders who take high amounts of whey proteins. This is often down to additives such as high amounts of lactose and sweeteners.

2. Bad breath This is a telltale sign that someone is following a high-protein, low-carb diet, such as the Atkins or Dukan. The lack of carbs pushes your body into using glucose stored in your body fat rather than using the glucose from carbs you eat. This causes a metabolic process called ketosis, which produces an unpleasant smelly metallic or chemical taste in your mouth that is stubbornly hard to shift and requires vigorous brushing or flossing of your teeth.

3. Keto flu Complained of by followers of high-protein diets – mimics seasonal flu with symptoms such as lightheadedness, fatigue, headaches and nausea. These are a result of the body’s rapid excretion of sodium and fluids as carbohydrate intake is low and glycogen stores are depleted. Increasing sodium by 1-2g per day may restore electrolyte balance.

4. Diarrhoea Eating too much processed meat coupled with a lack of fibre from too few carbs or vegetables can cause the runs. You’re more prone if you’re lactose-intolerant and taking protein powders, or are eating too much fried or fatty meat, fish, and poultry.

5. Constipation High-protein diets can upset pooping schedules. This becomes an issue for your bowel health if you’re not going at least three times a week. The main cause is a lack of fibre from not eating enough carbs. Nuts, seeds and whole grains, rice and pasta, along with upping your veg intake will help keep things regular. Drinking plenty of fluids, especially water, is recommended.

6. Kidney stones High-protein diets can increase the risk of kidney stones and lower your body's ability to absorb calcium after just six weeks, a study at the University of Chicago found. This is because a high-protein, low-carb diet increased the acid load to the kidneys, raising the risk of kidney stones.

7. Feeling foggy or dizzy Glucose is your brain’s main source of fuel, so when you switch out carbs for protein, your brain may not get what it needs to think straight. You may find your brainpower is lower and it’s harder to stay focussed.

8. Gut issues The quality of protein powders vary, says Tracy. They often have a lot of additives, such as sweeteners which can impact our gut microbiome. "Protein snacks often aren't that high in protein and contain a higher amount of fat and calories so, depending on your goal, this might be costing in multiple ways," she says.

9. Weight gain You can lose weight quickly on a high-protein, low-carb diet but the results aren’t always long lasting. When you eat too much protein your body stores it as fat, which can lead to weight gain over time. One study found that weight gain was significantly associated with diets where protein replaced carbohydrates but not when it replaced fat.

10. Cancer is the most serious side effect. High intakes of processed and red meats are linked to increasing risk of bowel and breast cancer. It's recommended we limit red meat to no more than about three portions – 350-500g (12-18oz) – of cooked meat per week. Switch red meat for lean chicken or plant-based proteins, such as tofu, nuts and eggs.

How to avoid problems

Eating protein to extremes, or any of the macronutrients, can put your nutritional needs out of kilter. It’s best to stick with a well-balanced eating plan. Follow these guidelines and adding protein supplements won’t be necessary unless you’re training intensely.

Tracy says that learning to work with your body is equally important. "Hyper vigilance can lead to disordered eating. Emotional awareness is also important," she says. She recommends these checks and balances:

• Know your goal (this often gets lost when following influencers/social media trends)
• How does it align with lifestyle/family/work?
• Is it a trend or can you sustain it for the long-term?
• If it’s a short-term thing, set the timeline and results you want to achieve
• What are you prepared to commit to?
• What do you need to believe to make a goal become a reality?

When it comes to exercise and diet, it pays to assess your challenge and adapt your eating plan accordingly. It’s important to fuel correctly and at the right times – that’s where you win and see results. Protein is only part of the equation.