The internet is full of quick-fix weight-loss hacks. One popular suggestion is to eat ‘negative-calorie’ foods such as celery, because you burn more energy eating and digesting the celery than you absorb. Is it true that eating some foods makes us lose calories rather than gain them? And does eating these foods help weight loss? We asked 3 experts in nutrition and physiology, ‘Do negative-calorie foods exist?’, here is what we found. This consensus is based on 3 experts answers from this question: Do 'negative-calorie' foods exist?What are calories and what are they for?Dr Louise Dunford, an expert in nutrition and physiology from De Montfort University in the UK, says “A calorie is a unit of energy, usually expressed as kilocalories (kcal) for the energy content in food.”. Most food packaging comes with labels that describe how many calories are in that product. We consume calories by eating and use calories by burning energy.Dr Dunford says “Our energy needs are made up of three components:

Coconut oil has had a meteoric rise in popularity thanks to its ‘superfood’ marketing angle, but it's not a miracle health elixir. On balance, it should be viewed as not much different from other sources of dietary saturated fat and does not make for a health food choice. This consensus is based on 5 experts answers from this question: Is coconut oil unhealthy?Coconut oil is attracting a lot of attention for its many claimed health benefits. Fuelled by celebrity endorsements, this ‘superfood’ claims to help you lose weight, boost your immune system, prevent heart disease, and protect you against Alzheimer’s disease. Many of these health claims are marketing hype being well advanced of the science. Coconut oil is a pin-up food to showcase the power of the Internet to propagate any food to ‘superfood’ status.A healthy saturated fat?Coconut oil is very high in saturated fat, at around 90 percent. Some claim that the type of saturated fat found in it is healthier than other types of saturated fat so it doesn’t represent a risk to cardiovascular health. Is this true?

Foods high in antioxidants are also high in thousands of other plant chemicals that have a multitude of physiologic effects on the body. It is the diversity of foods that matter most for good health, not their antioxidant content. This consensus is based on 5 experts answers from this question: Are foods with antioxidants in them really as important as they're made out to be?Antioxidants have been big news for many years. With promises of preventing and treating many diseases, it is no wonder that they get top billing when assessing the health merits of food. Antioxidants do serve important roles in our body. One of these is helping to mop up excess free radicals. Free radicals are unstable molecules that can damage cells. They form when atoms or molecules gain or lose electrons. Free radicals can damage other molecules as it seeks out electrons to stabiles itself.The body can cope with some free radicals, and even needs them to function effectively. However, the damage caused by an overabundance of free radicals over time may become irreversible and lead to certain diseases including heart disease and some cancers.Free radicals are damaging

Unless someone has coeliac disease, there is very little evidence to show that gluten is unhealthy or needs to be eliminated from the diet. Foods containing gluten can be key part of a healthy diet. This consensus is based on 37 experts answers from this question: Is Gluten unhealthy?Gluten-free diets are the cornerstone of managing the very real and serious autoimmune condition of coeliac disease. Putting coeliac disease aside, a person could be forgiven for thinking that we are now faced with an epidemic of self-diagnosed ‘gluten intolerance’ judging by the popularity of gluten-free diets.For the approximate 1 percent of the population with known coeliac disease, the immune system reacts abnormally to gluten (a protein found in wheat, rye, barley and oats), causing small bowel damage. A strict, lifelong gluten-free diet is currently the only recognised medical treatment for coeliac disease. By removing the cause of the disease, a gluten-free diet allows the small bowel lining to heal and symptoms to resolve.Is gluten-free better for you?

Saccharin – the first artificial sweetener - was discovered by accident when, in 1879, Professor Ira Remsen from Johns Hopkins University noticed a sweet substance on his hands after experimenting with different chemicals in the laboratory. Saccharin quickly became extremely popular, mainly due to how cheap it was. It was particularly widespread during World War II, when real sugar was in short supply. Today, artificial sweeteners are central to the huge market of diet and sugar-free food and drinks. Their attraction today is not only how cheap they are, but their potential to combat the increasing threat of obesity and its associated health impacts. Saccharin is over 200 times sweeter than sugar but has zero calories. Does this mean that we should replace all sugar with artificial sweeteners? Or are there more factors to consider? We asked 8 experts “Are artificial sweeteners better for you than sugar?”. The consensus was 63% ‘likely’. Here is what we found out. This consensus is based on 8 experts answers from this question: Are artificial sweeteners better for you than sugar?What are artificial sweeteners and how do they work?Artificial sweeteners provide the sweet taste of sugar but without the calories. There are two broad categories of artificial sweeteners: sugar alcohols and high intensity sweeteners. Sugar alcohols are structurally similar to sugars but less readily metabolised, whereas high intensity sweeteners are small compounds many times sweeter than sugar. The high intensity sweeteners include saccharin and aspartame.Even though artificial sweeteners provide minimal to no calories that does not mean they are inert. Artificial sweeteners interact with the T1R-family of sweet-taste receptors in the mouth and gut, which can have metabolic effects. They may also interact with the bacteria that make up the gut microbiome. Different sweeteners might differ in their effect on the body.