Ah fair enough. Regarding olive oil and cream, these are staple components of a ketogenic soylent diet (and high fat is a large part of keto in general), so you may want to look into reports of safety of those if you’re unconvinced.
Regarding specifically oil and cream though, olive oil is predominantly monounsaturated fat, whilst double cream is predominantly saturated.
Contrary to popular belief, recent studies and meta-analyses have shown that saturated fat isn’t as harmful as previously believed (some going as far as to say not at all). The conclusion of this study (http://www.bmj.com/content/351/bmj.h3978) stated the following: “Saturated fats are not associated with all cause mortality, CVD, CHD, ischemic stroke, or type 2 diabetes, but the evidence is heterogeneous with methodological limitations.”. However other studies arrive at different conclusions. If interested, perhaps browse the studies linked on this Wikipedia page on the matter: https://en.m.wikipedia.org/wiki/Saturated_fat_and_cardiovascular_disease_controversy
In contrast, monounsaturated fats have never had their benefits really called into question, as they are pretty much regarded as healthy by everyone. This makes analysis of the benefits/risks more challenging, but I was able to find the following quotation in the summary of this journal article (http://circ.ahajournals.org/content/100/11/1253#sec-8): “There is epidemiological evidence that dietary MUFAs have a beneficial effect on the risk of CHD. Moreover, evidence from controlled clinical studies has shown that MUFAs favorably affect a number of risk factors for CHD, including plasma lipids and lipoproteins, factors related to thrombogenesis, in vitro LDL oxidative susceptibility (compared with PUFA), and insulin sensitivity. Compared with SFA, MUFAs lower total and LDL cholesterol levels, and relative to carbohydrate, they increase HDL cholesterol levels and decrease plasma triglyceride levels.”
If your bigger concern is simply the overall fat content of the diet as opposed to the types, this is harder to prove or disprove of being unhealthy. Generally fats are now regarded as a good source of calories, and many of the studies that determined otherwise were conducted around the 60s and 70s and were funded by sugar companies who wanted to divert attention away from the fact sugar was the cause of obesity and diabetes - it is no coincidence that since doctors (and others) recommended high carb, low fat diets for weight loss, there has been a huge obesity epidemic in most of the western world. However, this conclusion is more drawn from correlation than studies, so again, it’s more questionable.