For everyone desperately seeking slimming advice from Instagram foodie influencers: don't bother.
It's not much use trying to follow your family's advice on what they eat to stay slim, either - even if you're an identical twin.
Even sticking to standard dietary guidelines - cutting down on fats and carbs, and meticulously counting calories - is something of a shot in the dark at what your body really needs.
According to groundbreaking new research, the nutrients on our plates have very little influence on our responses to food, and our genes only determine about 50 percent of our reactions.
What's more, while some of us would do well to cut down on fats, others would be better off watching their carbs, and some needn't bother at all.
In fact, the most important factors that determine whether we will put on weight, develop diabetes, or suffer indigestion are environmental - including stress, sleeping patterns, exercise, and what bacteria live in our guts.
The study, the latest in a near 30-year endeavor by Kings College London epidemiologist Tim Spector, is one of the strongest endorsements to date that personalized diets are key if we want to truly control a person's risks of obesity and other diet-related diseases.
Our gut bacteria is influenced by a myriad of things, and those things all influence our health dramatically. It means someone else's diet plan may not work for you (file image)
Dubbed 'Predict', the project is the largest ever to analyze what influences individual responses to nutrients, involving 700 identical twins, another 300 Brits, and 100 Americans.
The full findings have yet to be published, but the team shared some details at a conference on Monday, shattering many of our firmly-held beliefs about genes and food in the process.
Working with a team at Harvard Medical School, Spector, the founder of the British Gut project and Twins UK (both exploring the same question), found diet needs to be highly personalized if it's to have an effect on how we look and feel.
Over two weeks, they studied how each of their 1,100 participants' blood levels reacted after every meal. They compared this data with a record of each person's exercise habits, sleeping patterns,
