Sex education will become compulsory for school children from September 2020, the Government has announced.
Pupils as young as four are to be given lessons in well-being and healthy living, according to Department for Education (DfE) proposals.
Health education will be a mandatory part of the curriculum for all primary and secondary schools in England from autumn 2020.
Under the plans, which are now open to consultation, pupils will learn about "resilience" and well-being to help guard against mental health issues.
Classes will also cover physical health, such as the importance of exercise, and healthy eating and the benefits of a healthy lifestyle as well as preventing health problems.
The proposals are being published alongside draft guidance on relationships and sex education.
Education Secretary Damian Hinds said that good physical and mental health is "at the heart of ensuring young people are ready for the adult world".
"By making health education compulsory we are giving young people the tools they need to be ready to thrive when they leave school."Under legislation passed last year, relationships education is now compulsory in all primary schools, while sex and relationships education is compulsory in secondaries.
As part of the move, guidance on the subject is being updated, amid concerns that the current advice is out of date and fails to address modern day issues such as cyber-bullying, sexting and online safety.
Primary school pupils will also learn about the perils of social media, according to the proposals.
All age four to eleven-year-olds should be taught a set of rules and principles to protect themselves online, the draft guidance will say, as well as how to spot risks and harmful content.
Pupils at primary school should also be taught why computer games, online gaming and social media sites have age restrictions, it will add.
Last year, the Government tabled an amendment to the Children and Social Work Bill as early as today that will make "age appropriate" sex and relationship education (SRE) part of the English national curriculum in primary and secondary schools.Ministers have faced mounting pressure from across the political spectrum to bring about the change, following concerns children are being left ill-equipped to cope with the new realities of online porn, cyber bullying and sexting.
It will become a statutory requirement for all school children to be given sex and relationship education classes from September 2020.
Currently only pupils attending local-authority run secondary schools, which represent around a third of secondary schools, are offered sex and relationships education.
-- Camilla Turner, education editor