The Love Actually actress has always looked incredible, but maintaining a healthy lifestyle hasn't always been easy for the mum of two.
Back in 2009, Emma told the Daily Mail that she's not a fan of her 'great big zonking bottom', and that she runs practically every day so she can 'drink wine' and eat what she 'bloody well want[s] - because around 40, everything changes.'
Emma, 57, went from a size 14 to a size 10 in only six weeks by using the same diet coach as Kate Middleton.
The Method, crafted by Louise Parker, shuns the superfood craze and focuses on an 'anti-diet' approach.
Combined with intensive exercise, the weight loss course costs £4,500 for six weeks - and Emma has complete faith in its amazing results.
There are four main principles of The Method: wellbeing and good sleep, intelligent exercise, diet and mental positivity.
So, what exactly did Emma do for her fabulous transformation?
Make sure your weight loss approach is the right one for youIt's clear that Emma has placed her absolute confidence in guru Louise Parker, having been quoted in Louise's latest cookbook as saying:
'Louise is the only one out there I trust - she's not holier than thou, yet somehow miraculously gets my reluctant arse into gear and sometimes even keeps it there.
'I love that her method is NOT a diet - and is genuinely sustainable - so I can have my glass of wine and manage to avoid spending the rest of the week eating cheesy Wotsits.
Left: Emma in 2009. Right: Emma at the premiere of Bridget Jones' Baby in September 2016
'She toughens me up without driving me round the bend with kale juice and the more depressing style of sprout. She just gets it. We all use her, because she's discreet and funny and that's really important.'
Don't go along with fads - make wise nutrition choicesThe Method avoids foods that have been placed on a health-pedestal - no chia seeds, gluten-free or paleo foods, or kale smoothies here!
Devotees of the 'anti-diet' can enjoy the food they love in moderation, including bacon, cheese, and even a glass of wine every so often - Emma in particular is partial to some picpoul de pinet!
Emma has a calorie-controlled diet, consisting of three protein-rich meals a day with carbs and a little bit of healthy fat, and two snacks.
Emma at an awards ceremony in early 2016
Louise mentions in her cookbook that she's aiming to break down the health myths surrounding nutrition today.
'Basically I'm on a mission to stop people being organically overweight,' she says.
'That is, eating gluten-free, nut-free, dairy-free, paleo-friendly, chia seed-this and cacao-that things, thinking they're doing all the right things. Instead, they're simply getting fatter, and it's madness.'
Break a sweat, then get some sleepAs part of Louise's course, Emma had six lots of 90-minute resistance training sessions, which involved weights and ballet-like moves.
Emma was also weighed every week using some bioelectrical impedance scales, which monitor body fat and muscle weight.
Emma at a premiere in early 2016
Good quality sleep is also important after all of that hard work, according to Louise.
'Sleep is a crucial element, as is a digital detox at night. Kindles and mobiles are out, and instead we encourage people to read good, old-fashioned books in bed. It's all boringly simple really, but very do-able.'
Keep up the fantastic work, Emma!