Hi and thanks for your query.

If you go over your suggested daily intake of fat on a particular day because you’ve eaten a food containing ‘good fat’ such as mackerel, don’t worry unduly as it's is the total calories you consume that are critical to weight loss.

The reason certain fats are classed as 'good' is because of the positive effect they seem to have on blood cholesterol levels. A food containing 'good fat' is unlikely to increase the risk of heart disease in the same way that foods containing 'bad fat’ do. Examples of foods that are high in saturated ‘bad fat’ are meat products, dairy (butter), coconut and palm oils, cakes, chocolate and pastries etc.

By comparison, mackerel is unusually high in fat, but these are good unsaturated fats that help keep the heart and circulation healthy. Other ‘good fat’ sources are nuts, seeds, pulses, grains and most vegetable oils.

Although ‘good fat’ is better to consume than ‘bad fat’, it's still fat which is the most dense source of calories - with 9 per gram. This is the reason we track total fat in the food diary. Reducing the overall amount of fat you eat has a biggest effect on cutting the total number of calories in your diet. So comparing a food with ‘good fat’ like mackerel with say pastries (‘bad fat’), the calories in the fat are the same, that is, its impact on your weight loss, it is just the effect on your blood cholesterol level that is different.

General healthy eating guidance is that no more than a third of your total daily calories should come from fat. This is what our fat figure is based on to ensure that you don't overdo the bad artery-clogging, saturated fats.

You should treat the figure as an upper limit – it is not a requirement that you must eat the full amount every day. Keeping your fat intake within the guideline we set makes it more likely you're eating enough of the less energy-dense food groups such as carbs and proteins - these also help to fill you up.

So in summary – aim to stick to your daily fat limit, but on days when you've slightly breached this due to an excess of good fats, don't worry. Keep having one-two portions of oily fish a week, plus some nuts and seeds as this is very good for you!

I hope this helps!