Sweeteners aren’t bad for you and white bread is OK – the doctor busting modern health myths

Blood sugar spikes are bad. The carnivore diet is best. Seed oils are inflammatory and cause cancer. If you are interested in nutrition then you might agree, disagree or be unsure about the above assertions. Dr Idrees Mughal, aka Dr Idz certainly knows what he thinks: “Those three myths are probably the most prevalent across the nutrition space right now.”

Disseminating nutrition information was a hobby on the side of his clinical practice as a doctor, but three years since taking to social media, it has taken over his life. Fighting the spread of nutritional misinformation has seen him grow a following of 1.8 million on TikTok and 295,000 on Instagram. 

Armed with a medical degree, a masters in nutritional research and a certification by the Board of British Society of Lifestyle Medicine, the 28-year-old from the West Midlands is beating back the quacks with science. 

“Obviously you get a small majority of people saying, ‘You’re a Tik Tok doctor, not a real one’,“ says Dr Idz. “But part of our training is knowing how to disseminate accurate health information. And arguably the best format to do that is on social media.”

Sixty per cent of the general population look to the internet for their health advice. “That shows the public mindset has shifted. And we need to go that way to meet them.”

Here are eight nutrition myths that Dr Idz wants to bust.

Myth 1: You need a ton of protein to gain muscle

For those who are training towards exercise or strength goals, there is a lot of confusion and misinformation about how, what and when to eat around your training in order to optimise performance in the gym and make those coveted gains in muscle.

The first thing Dr Idz makes clear: “You can eat as much protein as you like, as often as you like, but if you’re not working out in the gym at the right intensity and volume, you’ll reach a growth limit very quickly.”

Second, the amount of protein you require to grow will depend on the situation, the stakes (i.e. are you a recreational athlete or a high-stakes competitor?) and your goal.

“The sweet spot is 1.6g/kg,” explains Dr Idz. “Going above this to 1.6–2.2g/kg is perfectly fine, but it follows the law of diminishing returns; you’ll only get minor benefits.”

So for an adult weighing 80kg, consuming 1.6g/kg would equate to 128g of protein. “In real food terms, that’s the equivalent of two chicken breasts and a pint of milk. For the vegans out there, we’re talking a soy protein drink, a block of tofu, a cup of lentils and some oats.”

“I used to think that animal protein is far superior to vegan protein when it comes to strength and muscle outcomes. But when you match gram for gram, once you go above 1.6 kilograms it really doesn’t matter. Control studies have shown that when you compare a high-protein plant based diet with an omnivorous diet there is no significant difference in muscle outcomes.”

It is common to see recommendations that are a lot higher. “You see some online fitness guys recommending a gram per pound, which is 2.2 times more than a kilogram. You would have to eat 240 grams of protein a day just to meet the minimum level that they’re saying. That’s ridiculous. I wouldn’t feel comfortable eating that much.”

There are a few criteria where you need more protein. “If you’re actively losing weight and in a calorie deficit, eating more protein will help you reduce muscle loss that happens on a weight loss diet. In that case you should go to around 2.2 grams per kilogram,” says Dr Idz. “And if you’re an elite bodybuilder there’s some evidence that going up to 3 grams will preserve muscle mass. But we’re looking at 0.1 per cent of the population there.” 

Myth 2: Probiotics will fix gut issues

Emerging science around the gut microbiome has been changing how we all think about health. It’s also sparked an industry producing probiotic pills, powders, capsules and drinks that promise to boost your gut flora. Are these a waste of money? Dr Idz thinks so. 

“Consuming probiotics is akin to putting a drop of boiling water in a swimming pool and expecting the water to be boiling,” he says. 

We contain trillions of bacteria in our bodies. Most probiotics won’t come even close to that number. “Expecting a random strain of bacteria to have any significant impact on your gut microbiota is really lazy science.”

There are some demographic exceptions though, where a few probiotic strains have shown benefits, such as in neonatal intensive care units to reduce the likelihood of a baby developing necrotising enterocolitis, and also for some sufferers of irritable bowel syndrome. 

However, for the vast majority of people, he adds, “picking up a random probiotic and expecting it to fill the gap in your microbiome, you’re going to be wasting a lot of money”.

Commercially manufactured probiotics generally do very little because manufacturers often select bacterial strains that are easy to grow in large numbers over ones which  are adapted to the human gut. 

That’s not to say you shouldn’t eat foods such as kefir, kimchi and sauerkraut and drinks such as Yakult. “These are foods that will stimulate proper peristalsis of your bowel and have other nutrients in there. What I’m talking about are the pills.”

Myth 3: Intermittent fasting only works because you are eating fewer calories 

To fast or not to fast. Currently the main benefit of intermittent fasting (IF) is believed to be how it serves to limit calorie intake by restricting your time eating window. 

However, says Dr Idz: “IF does appear to be superior to a simple caloric restriction wherein a person eats fewer calories but at whatever time of day they like.”

Some of the reasons that scientists are working to find robust evidence of include how IF allows the body to slow down into ‘repair mode’ and turn on something called autophagy, which acts to clear out damaged cells and induces life-preserving changes. “The connection between IF, autophagy and cancer is an important area of research that’s unfolding.” 

There is also the idea that IF keeps insulin levels to a minimum, which allows the body time to burn fat. Shifting your eating window to the beginning of the day in particular will have benefits. “Our body is not as capable at regulating our blood sugar levels closer to our ‘circadian night’, or within a few hours of the time we normally sleep,” Dr Idz explains. 

Chrononutrition, the science of meal timing and how it affects nutrition, counts. 

In a 2018 trial, eight men with pre-diabetes underwent a five-week study in which they all ate the same meals in a controlled environment. Each man was given either a six-hour feeding window that ended before 3pm, or a 12-hour feeding window that included eating late into the evening. The study found that those who stopped eating at 3pm had improved insulin sensitivity, beta-cell responsiveness (the cells within the pancreas that are responsible for releasing insulin), blood pressure, oxidative stress and a reduced appetite. “These results suggest that confining your meals to the earlier part of the day may aid in blood glucose regulation, cardiovascular health and weight management,” says Dr Idz. 

Busy, working lives have shifted our main meal to the evening, but if possible, Dr Idz advises making breakfast the main meal of your day will confer benefits. 

Myth 4: Seed oils are all terrible

Rapeseed oils and vegetable oils have been put on the naughty step due to fears around omega-6 inflammation.

The hypothesis is that the body converts the most common omega-6 fatty acid, linoleic acid, into another type of fatty acid called arachidonic acid. The latter has been implicated in increasing the number of pro-inflammatory cytokines in the body. However, this conversion process has only been demonstrated in animal studies. “People have inappropriately attributed these effects to humans,” says Dr Idz.

In fact, he adds: “No matter how much linoleic acid you consume, meta analyses have shown that increasing your linoleic consumption by 500 per cent has zero difference on how much arachidonic acid your body produces. The process is highly inefficient. That’s why analysis shows no matter how much you consume it  has no impact on blood levels.”

Secondly, it’s important to remember that seed oils are not all omega-6 fats. “Some only contain 30 per cent omega-6 fat.The majority of them are actually monounsaturated fatty acids (MUFAs).”

The fear around seed oils has arisen because of the focus on one component of them. “You have to look at the ratios of all the nutrients and research that tests the whole food.”

When all the major cooking oils were tested (including canola, peanut and corn oil), all were found to be more effective at reducing total and LDL (bad) cholesterol compared to butter or lard.

“This means that they are effective at reducing risk factors implicated in conditions such as heart disease and diabetes, especially when used as substitutes for other fats.”

Several studies demonstrated that vegetable oils can have an anti-inflammatory effect, with none of the 10 human studies assessed showing an inflammatory response.

If you heat a seed oil up and keep it at a high enough temperature for a long time, like you would in deep-frying, Dr Idz states: “You can absolutely cause the formation of trans-unsaturated fats.”

These are inherently damaging to our health, increase the risk of heart disease and death, and are indeed pro-inflammatory in nature. “However, in everyday cooking like pan-frying or roasting, this conversion process to trans fats just won’t happen.”

There reputation has also been tarnished by their use in ultra-processed foods (UPFs). “We add fats to food to make them taste better and last longer and as a stabiliser,” explains Dr Idz. It is not the oil itself that’s unhealthy, but that it’s used in foods that do not promote satiety.

Myth 5: To fix obesity all you have to do is move more and eat less

Scientifically, no one can argue with the mechanism of this statement, says Dr Idz: “At some point if you continue eating less and start moving more the scales will shift and you will lose weight, that’s just how our physiology works.”

However, he believes it is an oversimplification of what we need to do to lose weight. The eat less, move more argument he likens to telling someone who is depressed to feel happier. 

“It’s not helpful because it puts the blame on the end consumer and ignores the other factors that influence people’s choices; such as food policy and the cost of living crisis.” There are also genetic reasons why some people feel more hungry. 

“The fact is food manufacturers are making the most calorie-dense, tasty foods the cheapest. And the most minimally processed healthy foods are more expensive. How can you expect someone to improve their diet when they can’t afford it?”

Dr Idz believes a step forward would be for the Government to force industry change that will help consumers with better outcomes. “We’ve seen this with the sugar tax. We now know that seven out of 10 soft drinks in the UK now contain zero sugar because the Government made it clear to food manufacturers that if they kept high sugar levels high they would have to pay more per product.”

So while it’s true that eating less and moving more will help you lose weight, Dr Idz says that in application, it’s not always that simple. 

Myth 6: White bread is bad for you

The humble loaf of sliced white bread has been banished from the shopping baskets of the health conscious; labelled as highly processed and pilloried for its list of additives to prolong shelf life. 

Dr Idz isn’t a fan of defining foods as either good or bad. “There are some fortified white breads with Vitamin D in them, with decent amounts of fibre and 2-3 grams of protein. So it really depends.”

If at the extreme end, a ‘bad’ slice of white bread has 25 grams of carbohydrates and 2 grams of added sugar and no other vitamins or minerals. In that situation Dr Idz advises: “You have to remember that bread is just energy. It will break down to glucose.”

But context is key: “How many people do you know sit on the sofa munching slices of bread? Not many people do that.” Most people will eat bread as part of a balanced sandwich. “Obviously having a loaf of bread by itself every day is not going to benefit your health. You’ll probably be over consuming calories and it’s not very nutritious. But if you’re having it as part of a lunch sandwich with lettuce, grilled chicken breast, a little bit of low fat mayonnaise and maybe some pickles and relish, that’s completely fine. That’s a balanced meal.”

Myth 7: Artificial sweeteners are bad for you

Diet fizzy drink lovers everywhere panicked last year after a French study linked aspartame to cancer. Similarly, many of us promptly stopped using sweeteners in our tea, but did we need to?

Artificial or non-nutritive sweeteners such as aspartame, sucralose and acesulfame potassium and their impact on health is one of the most controversial topics in the wellness space today. 

However Dr Idz says: “There is no strong, controlled research ever showing that artificial sweeteners have any deleterious effects.” 

A 2016 study of two groups, one drinking a litre of water a day, the other a litre of artificially sweetened drink a day found that the sweetened water group lost three times as much weight as the water group. 

How was this possible? “It’s because they serve a very good role in diminishing sweet cravings.” Dr Idz himself drinks artificially sweetened water. “I used to have a huge sweet tooth. I would have cookie dough and ice cream four times a week. Now I have it once a month.” 

The paper that caused a stir last year linking aspartame and cancer was based on observational evidence of 100,000 people over a decade: “The issue with that is you can’t negate the impact that reverse causality can have on cancer. Is the artificial sweetener causing cancer, or is it that the demographic that uses them has a higher risk of cancer in the first place? They’re called diet drinks for a reason. They are targeting people who want to lose weight.”

JECFA is an international scientific committee administered jointly by the Food and Agriculture Organization of the United Nations (FAO) and World Health Organisation that has advised that it is safe for a person to consume 0-40 milligrams for every kg of body weight each day.  A person weighing 70kg would need to drink more than between nine and 14 cans of diet soft drink a day to exceed the daily guideline.

Another criticism is that they damage the gut but Dr Idz explains that aspartame doesn’t even reach the large bowel: “It gets absorbed very quickly, so it can’t even affect the gut microbiome.”

While some people with IBS may be sensitive to some sweeteners, Dr Idz goes as far as to say: “I could even argue that artificial sweeteners for the average overweight person in the western world would probably reduce the risk of diabetes and cancer because you’re helping individuals to lose weight.”

Myth 8: Humans aren’t supposed to drink cow’s milk

The line ‘humans are the only species to drink another mammal’s milk’ is frequently used to imply that this is because our dairy consumption is unnatural and therefore bad. “It’s a silly argument and again, the appeal to nature fallacy,” says Dr Idz. “Humans are also the only species to cook their food, drive cars, eat at restaurants and obtain information from social media. Should we stop doing all of that too?”

Dairy has consistently been shown to have a neutral or even anti-inflammatory effect. “Not all saturated fats are created equal,” Dr Idz explains, and the inflammatory potential of incorporating a variety of dairy products into your diet is not something to worry about.

It is also a quick and easy way to obtain lots of essential nutrients. “In many poorer parts of the world, milk is literally the thing keeping people alive.” 

Dr Idz is himself lactose intolerant; he drinks lactose free milk. “I love it. Milk is an accessible, affordable nutritious drink that doesn’t require much work to get.”

However, if you do experience negative symptoms with dairy, you might want to trial lactose-free dairy options or consider an elimination diet. “To do this, simply cut out all dairy for a few weeks while keeping other dietary habits constant, and check if your symptoms resolve. If you like, you can then try to slowly reintroduce dairy products over time, to see if you’re able to tolerate them.”

Saturated Facts by Dr Idrees Mughal (Dr Idz) is published by Penguin Life.