It’s not news that eating a whole bar of chocolate in one sitting isn’t good for you, but it’ll probably come as a surprise to hear that eating too much of some healthy foods can have some unwanted side effects. We KNOW.
There’s no need to totally freak – they’ve still got huge benefits in moderation - but here’s what could happen if you overdo it…
Yep, according to a study by Teresa Fung at the Harvard School of Public Health, kale is high in thallium – a toxic metal – and can lead to "fatigue, skin problems, gluten sensitivity and lyme disease". Fret not, though, chowing down on (let’s admit it, tasteless) leaves hasn’t all gone to waste – Fung suggests sticking to three-four servings a week, while Cassandra Burns, a clinical nutritionist at The Nutri Centre, adds that the vitamins in kale contribute to an impressive immune system, good bone health and healthy bowels.
Oranges and tomatoes
Acid, acid, acid. As researched by the University of Maryland Medical Center, these summer staples are brimming with the stuff, meaning that when we eat too much, we’re actually at risk of an acid reflux. Research by the University of California-Davis recommends that two-three servings a day is ideal, while they're are also "high in carotenoids" - vital for fighting inflammation.
When the Mercury Police Project investigated mercury levels in fish, the results showed that tuna contained a whole lot more than other types. According to the FDA, this can actually cause "impaired vision, hearing and speech problems and muscle weakness", but only if consumed in unhealthy amounts. Dr Gochfeld of the Environmental and Occupational Health Sciences Institute suggests mixing up your sandwich go-to for other fish such as salmon, pollock or shrimp to maintain a balance.
While hydration is key, drinking too much water can, in rare cases, result in water intoxication. However, before you start freaking out, it's very rare - the Clinical Journal of Sport Medicine says this is probably more applicable to marathon runners and people who force themselves to over-drink, but the best way to check is through your pee – if it’s ALWAYS clear, you are probably consuming too much…
As well as all the good stuff, Dr William Shaw of The Great Plains Laboratory explains that spinach is high in oxolate – a compound that can induce the formation of kidney stones. He adds that while there’s no hard and fast rule as to how much you should consume of this one, "stick to two servings a day and you’ll have nothing to worry about". Phew.
Lean animal protein
If chicken breasts and egg whites are your protein go-to, here's something to bear in mind. A study in the Centers for Disease Control and Prevention shows that too much animal protein could make your body produce more of a hormone which promotes ageing and the production of cancerous cells. This doesn't mean you should ditch chicken and eggs altogether though, simply look for protein in beans, nuts, seeds and whole grains as well.