to your 160.5 lovely so step forward Amy and Nancy are 24 year old twins so Amy and Nancy what we want to do is to look at how food processing impacts your health they're taking part in a test with Dr Sarah Berry and Professor Tim Spector from King's College London what you're going to do is for two weeks Nancy you're going to be doing the unprocessed diet and Amy you're going to be eating the ultra processed diet then we're going to get you back here and then we're going to do the same test again and look at how these different foods have impacted your health the twins diet will be matched exactly for calories nutrients fat sugar and fiber food accounts for more than 50 of our energy intake and it's an even bigger problem in children so it counts about 65 of our energy intake for children this is actually increasing at an alarming rate We Believe old processed foods are having an unfavorable effect on our health is because the actor processing Foods breaks down the structure of the foods often Ultra processed foods have very little fiber in them or the fiber is removed many of these ingredients most people won't have heard of but what we don't know is how all of these different chemicals might interact together in terms of our health I do eat some processed foods just out of convenience but I do love lots of freshers and have quite healthy diet I think so I think it is going to be a bit of a shift for breakfast this morning I had a quinoa porridge with berries on top and done a really good job of keep me energized and full so it's the end of the day now and I've got a bit of a headache to be honest so yeah ending the day still hungry feeling a bit sort of rubbish and yeah a bit of a headache lots of the things that you've just described about your headache all point to the fact that you're probably having what we call a glucose dip which is a dip in blood sugar that happens about two to four hours after people consume really heavily processed refined carbohydrates this is a mousse made with fruit puree and only 73 calories yeah you'd think that would be a healthy option oh my goodness pork gelatin glucose fructose syrup acidity regulator citric acid sodium hydroxide modified May starch there's a term we use called the health Halo where you you know you have packaging says uh high in fiber or low in sugar low in salt plant-based all of these kind of magic words that make people think wow these are really healthy if anything ever says low reduced or no I'd always be a bit suspicious because how else have they therefore made that food taste great in the last decade the evidence has been slowly growing that Ultra processed food is harmful for us in ways we hadn't thought the twins find there is one ingredient they keep seeing again and again on food packets and then emulsifiers again we've seen that a few times haven't they emulsifiers are essentially a glue they stick components together so that they have a good mouth feel and they don't fall apart in your mouth or on the plate so here we have carboxy methyl cellulose CMC which is one of the commonest emulsifiers used in the food industry I'm just going to demonstrate what happens when you just add water to it and it very rapidly becomes like a glue the food industry uses around 60 different emulsifiers to enhance the appearance texture and shelf life of ultra processed foods some are naturally occurring others are chemically produced it's found an incredible number of our foods and they are potentially harmful Dr matil TVA is leading one of the world's biggest studies into food additives publishing regular reports based on the health and eating habits of 174 000 people she's been looking at emulsifier's long-term impact on health the BBC has had exclusive access to the early results the yet to be verified by peer review but she says they're concerning we observed a significant associations between emulsifier intake and increased risk of cancer overall and breast cancer notably but also with a cardiovascular diseases in England Wales and Northern Ireland food safety is regulated by the food standards agency the FSA it says it's about to launch a public consultation on some emulsifiers a spokesperson for the food and drink Federation said food manufacturers take the health of consumers and safety of the food they produce seriously and adhere to the strict regulations in the UK all additives are independently and rigorously assessed to safety by the food standards agency before they can be used in food the results of the twins tests are now in Amy you are on the ultra processed food diet your results were really quite different to your sisters they were far worse your blood fat levels actually went up your lipids which are markers of heart disease they were increased your blood sugar was noticeably worse you actually gained weight nearly a kilogram and you actually lost weight it's a bit scary isn't it after only two weeks to sorts of results so just imagine what that would be over 20 years after just two weeks of the test the impact of Amy's Ultra processed diet will be fully reversible but the results are in line with a growing body of evidence linking chemical additives and Ultra processing to serious health consequences we already have the most obese children in Europe that means more type 2 diabetes more cancers more heart disease more misery more mental illness this really is a future time bomb there are now dozens of scientific studies warning of the dangers of diets high in Ultra processed food the twins test showed the potential impact these foods can have on you in just two weeks Esme Stallard BBC News