Opinions vary hugely on how much fat it is healthy to eat. The traditional guidelines tend to be along these lines, and I think that they're fairly sensible. The recommendation they make of 20-35% of calories from fat is quite a wide range, however, and some diets go a fair amount beyond that. The McDougall diet recommends only 10% of calories from fat, and at the other extreme, low-carb diets such as Atkins can have people on 40% or more calories from fat. The very low-fat diets tend to be plant-based and the very high-fat diets tend to place a greater reliance on animal foods. Health claims and research are all over the place, to the point that you can easily back up either end of the spectrum. This makes it rather hard to work out what to do! Taking for granted in this thread that it's all rather subjective, and that there's no point in getting into arguments about whether or not people should be vegetarians or what have you, here are some points to ponder. 1) Fat has 9 calories per gram, while protein and carbohydrates have 5 calories per gram. This means that eating a greater proportion of fat in the diet tends to lead to a higher number of calories. While weight control is affected by many factors, calorie consumption is the key one. Some people with ME tend to be underweight and some tend to be overweight. So a higher-fat diet may be easier to manage for some groups than others in this respect. 2) Fat helps make a meal satisfying, and for various reasons we definitely need some of it in our diets, although what the safe minimum is gets disputed. Fat can also make food addictive, especially in combination with salt and sugar. Again, this relates to weight concerns in fairly obvious ways. Sometimes it can be a matter less of how much fat you eat than what form it comes in and what it's accompanied by, in terms of how easy it is to stop at a sensible amount - I find it difficult to stop eating crisps (chips to Americans) or biscuits (cookies, more or less), but I will be perfectly satisfied by a stir-fry which happens to contain some almonds. 3) Arguments rage over exactly which types of fat are best for us and what forms they should come in. The main agreement seems to be that trans fats are bad, and that processing and over-heating are generally a problem. Some authorities claim that saturated fats are the best thing ever, others thing they are terrible. 4) There seems to be some haziness about the exact point at which a good fat turns bad due to heating or rancidity. Should we cook with our olive oil? Should we keep nuts and seeds in the fridge? 5) The brain is largely made of fat, and some of the most notable health claims for essential fatty acids are brain-related. ME folks could all do with any kind of brain boost we can get! EFA supplementation is one of the better-respected alternative treatments for ME, there are plenty of people who swear by it. 6) Essential fatty acids of the sort that are focused on for ME are mostly found in fish. There can be problems with contaminated oceans and so forth. Plant sources do exist, but tend to be rare and/or difficult to utilise. From what I've gathered, anyone who feels that they need more EFAs and who doesn't eat fish should probably get them from supplements rather than food sources. There are, of course, debates as to which is the healthiest form of EFA, how we should balance DHA with EPA and so forth. 7) There is a strong correlation between a high-fat diet and heart disease. While any dietary research of this sort is necessarily complicated - for instance, most research subjects out there eating high-fat diets over the last few decades were generally on fairly unhealthy diets overall, we're talking about things like the typical Scottish diet rather than legions of devoted paleo followers - it is still something to bear in mind, especially considering that heart problems are common with ME. 8) People with ME often have digestive problems. Sometimes these digestive problems include difficulty with digesting fats. Sometimes they cause other dietary restrictions, e.g. being on an anti-candida diet, being gluten-free, having to limit fibre. I wouldn't be at all surprised if most of the people in this forum have restricted their diets in some way due to illness. And a few more will have restricted their diets for other reasons, e.g. ethical/religious reasons or avoiding certain foods due to a family member's allergy. This can make it harder to get a good spread of nutrients from food, and can result in the diet needing to focus on certain areas. 9) This is thoroughly anecdotal, but I've heard that there may be a gender correlation with regard to problems with weight control, i.e. women with ME being more likely to gain and men with ME being more likely to lose. I've also heard that the ones who tend to be underweight often look quite jaundiced, and from having chatted to other people, it seems as if the ones who put on weight tend to put on disproportionate amounts of weight in their abdominal area (the more dangerous type of weight gain, and also more likely to affect hormones). 10) Paleo diets, which I believe tend to be relatively high-fat, are quite popular as a treatment for ME, though obviously they work well for some and not for others. My own history: I'm female and one of the people who tends to put on weight. I'm also vegan, and can we just agree now that we're not going to get into the pros and cons of ethical dietary choices. I think a lot of the weight gain was due to chaotic eating routines, though perhaps there was also a hormonal component. I have lost the excess weight over the past year by simple calorie-counting; I was already on a wholefoods diet, though I had the odd bit of snacking to contend with. My natural diet easily falls within the recommended guidelines for ratios of carbs/protein/fats. About eight or so months ago, I was diagnosed with gallstones, and told to eat a lower-fat diet in order to avoid gallstone attacks. So I became quite good at lower-fat cooking, counting out the almonds and avoiding avocadoes altogether. The gallbladder came out two months ago and I am now free to eat whatever proportion of fat in my diet that works for me. Since vegan protein sources tend to be higher in fat, the amount of fat I eat usually goes with the amount of protein I eat, and higher-protein diets are often recommended for ME. That said, the greater calorie density is difficult, since I need only 1400 calories a day in order to maintain my weight (I'm 4'11 and 100lb), which doesn't leave much wiggle-room. I'm curious as to how much fat I should be eating, within the limits of staying at a healthy weight and eating enough over the day to feel satiated. Obviously I'm only eating plant fats, but I'm sure there are many of us trying to balance this out who are also eating animal fats. Should I snack on almonds or toast, for instance? The doctors are no help, they know next to nothing about nutrition and just mutter vaguely about how they recommend everyone to be on a low-fat diet. What does everyone else think about this issue? Is there anyone who has experimented specifically with changing the amount of fat in their diet, without concurrently changing other factors (otherwise it gets too complicated to be sure exactly what has caused what), and if so, what have you found?