Become a weight loss super sleuth

Somewhere between “high protein”, “low fat” and “one of your five a day”, the front of a food packet can start to feel like a crime scene. Everyone’s making claims. Not all of them stand up.

The good news is that you don’t need a nutrition degree to crack the case. You need to know where the evidence is kept, and which clues to trust.

Clue one: the traffic lights

Many packs in the UK carry a front-of-pack label that colours fat, saturated fat, sugars and salt red, amber or green. It’s the quickest clue you’ve got. Mostly green and amber is a good sign. A red isn’t a reason never to buy something; it’s a reason to notice how much you have, and how often.

If a pack doesn’t have traffic lights, the nutrition table on the back does the same job. Look at the “per 100g” column and use these as a guide:

• Fat: low is 3g or less; high is more than 17.5g.
• Saturated fat: low is 1.5g or less; high is more than 5g.
• Sugars: low is 5g or less; high is more than 22.5g.
• Salt: low is 0.3g or less; high is more than 1.5g.

Clue two: per 100g beats per portion

Portion sizes on packs are chosen by the manufacturer, and they’re often smaller than what people eat. The “per 100g” column lets you compare two products fairly, side by side, whatever size they come in. Comparing two cereals, two yoghurts or two ready meals? Compare the 100g column.

When you do use the per-portion figures, check what the portion is. A “portion” of crisps might be half the bag.

Clue three: the ingredients list gives the order of events

Ingredients are listed from most to least. If sugar, or one of its aliases, is in the first three, it’s a big part of what you’re buying.

Sugar goes by a lot of names. Look out for glucose, fructose, sucrose, dextrose, maltose, honey, agave, fruit juice concentrate, and anything ending in “syrup”. A product can spread its sugar across several of these, so that no single one sits near the top.

Clue four: beware the health halo

Some words on the front of a pack are there to make you feel good about buying it.

• “Low fat” can come with extra sugar, added to put the flavour back.
• “Natural” has no set meaning for most foods.
• “High protein” snack bars can carry as much sugar as a chocolate bar.
• “No added sugar” doesn’t mean low sugar. Fruit juice and dried fruit are naturally sugary.
• “Light” only means lower than a standard version of the same food. If the standard version is very high, the light one can still be high.

Clue five: check your drinks

Drinks are the easiest place for sugar and calories to hide, because they don’t fill you up. Read the labels on juices, smoothies, flavoured coffees and “vitamin” waters. Water, milk, and tea or coffee without sugar are the safest choices.

Case closed

You won’t need to interrogate every packet for ever. After a few weeks of checking, you’ll know your usual shop by heart, and you’ll only need a closer look at new things.

That’s the moment you’ve become the sleuth: fewer surprises, better choices, and a lot less guesswork every time you shop.