Dr Kelly Johnston is our Head of Nutrition and Research and a Visiting Senior Lecturer at King’s College London. Her research interests are nutrition and gut physiology, obesity management, and the impact of diet on metabolic syndrome and other obesity-related co-morbidities.
Is intermittent fasting most effective at 4:3 or 5:2?
Certainly, if you do a 4:3 instead of a 5:2, you should be consuming fewer calories over the course of a week as you are effectively fasting every other day and assuming you don’t vastly overconsume on your ‘food’ days, you will likely lose weight faster. Some of the original research into fasting looks at the concept of alternate day fasting (ADF) which is similar to a 4:3 although these studies looked at fast days with zero food intake (i.e. no calories) and this particular approach wasn’t well-received by participants in terms of hunger, food pre-occupation etc. However, this is not the same as fasting 4:3 on LighterLife as you are fasting for fewer days per week anyway, and you are also consuming a balanced variety of food (albeit very low in calories) on those days too.
Remember, the most effective eating plan for any purpose; weight loss or weight maintenance, or just improved metabolic health, is always going to be the one that you can stick to. So, if three days of fasting per week is something that you can fit into your lifestyle and is working for you, great! If 5:2 is more your thing – then there is no reason to change this!
Can you suggest some low-calorie snacking options for smart days? What do you snack on?
As a rule, I am not a big snacker, but if I feel the need to eat between meals then my go-to snacks include boiled eggs, almonds, cherry tomatoes, vegetable sticks with dip, or various fruits including apples and berries. These foods are staples in our house and always available for myself and my children to eat.
Are there any types of snacks I should avoid?
Generally speaking, heavily processed snacks, which are often high in fat, sugar and/or salt should be avoided. So, steer clear of cakes, biscuits, pastry-based products are they almost always high in energy and but low in nutrition. Whilst these can be consumed and no food should be completely off-limits, they are best avoided whilst on a weight management plan.
Is it essential to snack, if so, how many calories should my snack be?
It’s not essential to snack no. If you aren’t hungry or don’t have to wait too long between meals, then snacking is of no real benefit as there is no need to consume calories just because the clock says it times for elevenses, or because somebody has brought in biscuits and cakes. Having said that, if you are starting to become hungry between meals, a nutritious snack is a good idea, as what it can ultimately do is prevent you from overeating on fatty, sugary foods, later. Very few people make good eating decisions if they become too ravenous and this is a real risk if you allow yourself to get too hungry as you’ll often grab what’s to hand. Snacking is also a really useful way to incorporate your five a day too – an apple and satsuma is a nutritious, tasty low-calorie snack which won’t sabotage your weight management plan.
What should the nutrition of a snack be made up of?
There is no one answer to this, and as nutritionists, we don’t look at meals in isolation, rather we look at intake over a day or even a few days. If you are attempting to stave off hunger then a high protein, high fibre snack is a good idea as it can fill a gap. Generally speaking, refined carbs are best avoided as they can leave you feeling temporarily sated, albeit short-lived and so you may find yourself reaching for another snack far sooner than you like.