NanKate that's an interesting question. You see some things which are high in sugar, such as tomato ketchup, you might only use teaspoonful, which might actually be less than something with lower sugar but you eat a big plateful of ('cuse grammar
)
You can either try to
1. Count actual grams in the food you eat and limit that to 25g (6 teaspoons)
2. Cut everything sugary you normally eat in half....eg just one biscuit not two, or a much smaller piece of cake, etc or
3. Forget all the counting and just cut out fruit juice, jams, cakes, biscuits, chocolate, fruit (1 piece a day), smoothies, dried fruit, yoghurt (except naturel) and everything you know in your heart of hearts contains sugar...and yes, honey is just as bad!!