As co-host of TLC’s “What Not to Wear,” Stacy London isn’t afraid to call out an ill-fitting pair of pants or some god-awful shoes. Her tell-it-like-it-is approach is all about helping people look and feel their best. In her new book, “The Truth About Style” ($33, Viking), London helps nine real women struggling with common wardrobe challenges (e.g., being petite, getting older).

What’s the difference between fashion and style?
Fashion is the industry that we look at and can be intimidated by, or participate in and feel like we’re never good enough. Style is about not comparing yourself to other people. It’s taking a nice, realistic look at who you are, assessing the things you don’t love about yourself, and starting from there.

Why do women need a style?
Think of your style as a calling card for who are, a gateway to opportunity. There are so many things in life that we can’t control. Why not take control of something easy and get some joy out of the way you can make yourself feel?

In the book, you tell women to accept themselves as they are before getting dressed.
If you’re not working with what’s there, you’re dressing in a way that’s ill-fitting or there’s a disconnect with your personality. Trying to dress like you’re 20 years younger or 20 pounds thinner is not where or who you are.

What’s a big roadblock when women go clothes shopping?
The idea of being psychologically attached to a number, whether it’s your age or on a scale or on a size label, will get in the way of your being able to enjoy fashion.

What role do our emotions play in how we dress?
We do a lot of that compare and despair stuff. The fact is, we get down on ourselves for any number of reasons. In a culture that prizes beauty and youth and wealth over anything else, we wind up comparing ourselves to unrealistic standards instead of being proud of who are.

Are there any key pieces all women need in their closets?
I believe in the power of three. If you’re doing separates, you create a complete outfit by having a jacket, cardigan or a statement piece of jewelry. It’s that period at the end of the sentence. I believe very strongly in fitted blazers, especially ones that have seaming that creates a waist. Leather jackets are an easy way to up the ante and make a blouse and trousers look chicer.

Workplaces in D.C. can be conservative. How can we stay stylish in the cubicle?
Accessories, accessories, accessories. Great shoes, a cool scarf or a great handbag are the biggest ways you can punch up conservative clothing. Shoes are really game changers. You could have the same black pencil skirt and wear it 40 different ways depending on the shoes.