Frequently Asked Questions

Not sure if the What IF Plan is right for you? Check out these Frequently Asked Questions covering intermittent fasting, nutrigenetics testing, nutrition plans and weight loss to make up your mind. Please do email us at if you want to find out more.

Do I need to consult my doctor before I go on the Plan?

If you have a medical condition, or are obese, we advise you speak with your doctor before starting the Plan.

Can anyone try What IF?

It’s not suitable for everyone. It’s only recommended for 18-75 year olds. Anyone suffering from an eating disorder, or who would be putting his or her health at serious risk by fasting, can’t do the Plan. Diabetics are only allowed with approval and supervision from their diabetic management team.

How much weight will you lose in the first two weeks?

Depending on how disciplined you are, you can lose between 5-9lbs in the first fortnight. Everyone will lose weight, but some people will lose it quicker because their bodies are built to burn fat at a faster rate – this is something the DNA test will reveal. The main thing to remember is this isn’t a quick fix – it’s a plan for life.

What percentage of your clients has lost weight?

Everyone who has tried this plan has lost weight. We have never had a client that hasn’t.

Can I go on the diet if I only want to lose a few pounds?

Most definitely. Many of our clients have shifted the difficult last half a stone on the plan.

How long can you do the Plan for?

Until you reach your goal weight – you repeat Phase 1-3 until you get to that point.

Do I have to count calories?

Not in the tradition sense. On Phase 1 there is no calorie counting. You just have to have a 16-hour gap between eating, so if you eat dinner at 6pm you can’t eat again until 10am. During Phase 2, during the alternate-day fasting you are restricted to 500-800 calories for 3-4 days of the week.

I have Diabetes – can I still do the Plan?

Only with prior approval and supervision from your diabetic management team. Anyone with diabetic complications (damage to eyes, kidneys or nerves in hands and feet) cannot do the Plan.

I’m pregnant / breastfeeding – can I do the Plan?

No, unfortunately it’s not advised for pregnant or breastfeeding women to do the Plan.

I have small children – can I still do the Plan?

When Kate was creating the What IF plan she found that Phases 1 and 3 was easy when looking after her two toddlers, but Phase 2 was hard as women are limited to 500-700 calories (men are limited to 600-800 calories). Her compromise was to still do the plan but just omit Phase 2 and repeat Phase 1 instead (no breakfast, fast overnight and morning). That’s the beauty of the Plan – it can be easily adapted to your lifestyle and circumstances.

I have a food allergy / intolerance – can I still do the Plan?

Yes. You just need to make us aware when completing the online form.

What happens if you’re on holiday during the Plan?

You can still do it, but might find Phase 2 difficult. We recommend just repeating Phase 1 or 3.

I’m vegan / vegetarian – do you have recipes that I can eat?

All the recipes can be tailored so the client supplements the protein source with a vegetarian protein source of their choice. We do not cater for vegans in the recipe section but they can still benefit from a food list and report detailing their DNA results, nutrition and lifestyle recommendations.

Can I do the Plan if I’m obese?

The Plan works well for anyone severely overweight but we advise they speak with their GP or medical practitioner first.

I can’t cook – does this matter?

No. The recipes are simple and quick. You also have your food list, which contains your recommended protein sources and portion size in grams, and also salad and vegetables.

Can I feed my children the foods from the list?

Absolutely. These are normal foods everyone can enjoy.

Can I go out to restaurants?

Of course! This is a fun plan and not meant to be draconian. The only time eating out might be tricky is during the fasting days in Phase 2. But we do give the option during this phase NOT to fast on the fourth day.

For example, you can just do three fast days (Mon, Wed and Fri) and enjoy yourself over the weekend. If a social event is coming up doing Phase 2, that’s fine too, you just extend it by doing an extra fast day. That’s part of the joy of the Plan – it’s flexible to suit your lifestyle.

Do I have to exercise as well as fast?

Keeping fit is good for so many reasons, and people need different amounts of exercise to mobilise their fat stores. During IF, resistance (also known as weight-bearing) exercise is important as it preserves fat-free mass, such as muscle.

What if I can’t exercise for health reasons?

Intermittent fasting is still very effective even without exercise. However, if you have a genetic variation where you need to work out more to boost fat burning, then you may find your progress is slower than with exercise.

It’s important to maintain muscle mass as this helps burn more calories and increases metabolic rate.

Examples of resistance exercise include: yoga, Pilates, HIIT (High Intensity Interval Training), BodyPump, high-impact aerobics, high-impact sports (wherever you are lifting your own body weight).

So you may find you are already incorporating resistance training into your lifestyle. If you don’t do any resistance training already we do detail in the Plan the body-weight exercises that you can do as a mini circuit at home, which takes around 10 minutes, three times a week.

Can I still drink coffee?

This depends on the genetic results.

I have a really sweet tooth – can I still eat cakes?

We look at an individual’s sugar preference and the genetic test helps to understand why some people reach for sugary treats more than others. The results can also help clients understand their behaviour and eat more mindfully.

The truth is, you won’t lose weight by eating cakes every day. It’s a very calorific food with lots of refined sugar, which has many negative effects including robbing the body of restorative B vitamins. So we always ask our clients to eat mindfully (think about each mouthful) and if they want a piece of cake once a week as part of their treat meal (at the end of Phase 3) then that’s fine – have it, and enjoy it.

Do I need to take supplements?

We may recommend certain supplements. This is an extra cost.

What if I don't like any of the foods on the list?

The foods list is extensive. There is a lot of variety. We have never had anyone say they don’t like any of the foods, so hopefully this will not be an issue!

If I’m having a bad day what kind of support is available?

You can contact one of our ‘Genetic Geniuses’ via email at with any questions you have.

Will I be hungry on the Plan?

You may feel a bit hungry during Phase 2 until you get used to the 500-700 calories (for women) and 600-800 calories (for men) a day.

What should I do if I feel hungry?

Listen to your hunger cues and eat one of the healthy snacks we suggest, or, if it is close to your next mealtime, just eat earlier than scheduled. If you can go four hours between meals that is preferable but there are some days when we all need something sooner. Listen to your body. Often hunger is confused with thirst. Drink a pint of water, wait 15 minutes and see how you feel.

Should I fast on days when I’m less busy?

It’s definitely easier to fast when you don’t have a physically demanding day ahead. But it’s also easier to not think about food on fasting days when you are busy and distracted. Speaking from experience, I recommend for mums who have very active lives looking after a toddler or two, to consume the higher end of the calorie range (700 calories) during the alternate-day fasting of Phase 2.

Are there any side effects?

You may feel hungry when you first start IF. It’s natural to feel hungry at the start and your body will get used to hunger with time.

Exercise-wise, it’s okay to train moderately when fasting. Keep the HITT workouts to Phase 1 and Phase 3 of the plan.

You may experience a headache, which is a common occurrence during fasting. Drinking enough water helps relieve the headaches in some cases.

Can I do the Plan if I live outside the UK?

Yes. We’ll send you everything you need for the Plan free of charge but you’ll need to cover the cost of posting your mouth swab to our UK lab.