I am as big a fan of fat, salt and sugar as the next overindulged urban male, but even I have my limit. I think the menu at Foxlow may have located it. And then laughed in its face. Imagine a Thunderbirds-style dial with the arrow puttering in the red zone to dramatic music full of blaring horns and staccato strings. That's where I was by the end of lunch.

Part of Foxlow's challenge is its antecedents. It is the newest sibling of the impressive Hawksmoor steakhouse group, against which it will always be compared. The Hawksmoor team have worked out how to shape a steakhouse that doesn't ape its American cousins. It's seared dead cow with a British accent, and a supporting cast to match. And it is unapologetic about the cost, which is as it should be when dealing with the very best meat and fish. But then they also deliver both on service – the bed-haired, fully inked staff are anything but casual about their job – and room. Hawksmoor has executed some of the best restaurant interior-design jobs of the past few years, cornering the market in reconditioned parquet and wood panelling.

Foxlow is billed as a "neighbourhood" restaurant, but as it's located in Clerkenwell – a neighbourhood for City University students who can't afford to eat here – I think they mean it isn't as flash than the others. And yes, it is less expensive. But at an easy £55 a head it certainly isn't cheap.

Again, they've done a serious job on the decor. It has been coated in acres of distressed creamware tiling and slatboard painted that shade of off-white gloss your grandma used to favour for the bathroom. It looks like a cross between an old French station café and a New England seafood shack. If all else fails they could sell it on as an abattoir.

While they do offer some of the same beef cuts from the Ginger Pig as at other outposts, here the menu divides up around titles such as "slow smoked" and "charcoal grilled". There's also a salad bar pace Garfunkel's, though it's only for show. You may walk past it; you may not touch. The result feels muddled and uncertain, as if it's self-consciously trying to be distinctive.

From the snacks, the anchovy and goat's butter crisps bring a trio of crackers piled with meaty, salted anchovy fillets topped with crisp rings of raw onion. They are a small hit of salt and dairy fat and, at the start of a meal, welcome for that. But then we didn't know what was to come. Alongside them, machine-sliced Tamworth "jamon" merely serves to remind you just how good real Spanish ham is, and how good this British knock-off isn't. It's served too cold, lacks depth of flavour, and has a compressed, plasticky feel, as if it has been pre-cut and laid out on cellophane sheets. The four slices cost £5.50.

From the starters, crispy five-pepper squid is indeed crisp, but much more salt than pepper. Brixham crab with devilled mayonnaise for £9 is a head scratcher. It's good fresh crab but not very much of it, that fact obscured by the amount of foliage – Cos lettuce leaves – it is scattered across. The devilled mayonnaise has about as much kick as me on the sofa at home, half a bottle down, by the time Newsnight comes on. And what's with serving a cold starter on over-warmed plates?

From the slow-smoked section, the eight-hour bacon rib with maple and chilli does the thing. It is a big strip of smoked pig that is falling away from the bone it calls home. Given my love of pork it was always bound to make me happy, at least at the start. There is not much chilli, but there is loads of salt and sugar and fat. And not much else. Literally. You pay £16 and get a big empty plate with a slab of meat lying across it. It has not been plated. It's been abandoned. That means the £3.50-£4.50 charged for sides becomes an unavoidable cost. So we get broccoli with chilli and anchovy. There's a massive blast of salty fish, and again not much chilli to cut through it. The beef-dripping potatoes are properly crisp. The capers are salty.

Look, at least we didn't order the skin-on fries with bacon salt. Or the sausage-stuffed onion. Even so, by this point I imagined my entire cardiovascular system had called a flash meeting in my bowel to discuss strike action over unreasonable employment practices. We ordered fish. That would be good for us, wouldn't it? Not if it's the house-cured salmon. No quibbles with the cooking. The skin is crisp, the flesh boasting a little pinky pearlescence at the heart of each flake as you prise it apart. But again it's a big hit of salt and sweet. And it, too, sits alone on the plate, marooned by acres of white porcelain. The only relief comes from a side-dish portion of the baked beetroot and hazelnut concoction from the salad bar. It is soft and sweet in a good way.

I studied the menu afterwards. I wanted to check whether this overload was down to an ordering cock-up on my part, but I'm not convinced it was. This place serves big fatty rillettes and pork ribs, beef short rib with salty kimchi, and anchovy and chilli butter. There's no doubting the quality of the ingredients or the execution in the kitchen or the general professionalism. One or two plates like this would hit the spot. It's about the cumulative effect.

Which carries on into dessert. There are sundaes made with their own version of soft-serve ice cream. We avoid the bourbon caramel, the peanut butter and jelly, and the chocolate and popcorn because they sound like too much sugar. Instead we get the cherry ripple, which is a bit of fruit bombarded by a lot of syrup. The banoffee split (look, we did steer clear of the peanutella and sweet toast) is a heap of cream, toffee syrup, biscuit, bananas and caramelised things. At which point I imagined my pancreas declaring itself an allied trade of the cardiovascular system and joining the strike meeting down in my bowel. I suspect that, were I completely sloshed, all of this would be fabulous. It would be great. I'd welcome every last speck of salt, fat and sugar. Sadly, that's not a great recommendation for what's trying to be a grown-up restaurant.