1.The Route Map states that “the degree of overweight or obesity is determined by the degree to which an individual is in positive energy balance over a sustained period i.e. energy intake exceeds energy expenditure. Therefore, a small persistent positive energy balance over a relatively long period of time can result in obesity” 
2. The Route Map states “to achieve sustained weight loss, for the majority of Scotland's population who are already overweight, requires both a change in eating habits to reduce calorie intake and an increase in physical activity. For adults, at least 60 minutes of moderate activity, such as walking, is required on most days of the week to both lose weight and maintain weight loss.” 
Although the evidence is uncertain on the best combination of services and interventions to implement locally, the evidence sources we have accessed all suggest that a range of actions tackling both diet and physical activity are required to reduce obesity. It is unlikely that change of the magnitude required could be achieved in either diet or physical activity alone. The logic models should be seen as setting out a combined multi-strand approach to reducing obesity.
NICE guidance on the prevention, identification, assessment and management of obesity in adults and children recommend that people should follow a range of strategies to make it easier to maintain a healthy weight by balancing ‘calories in’ (from food and drink) and ‘calories out’ (from being physically active). These include making physical activity enjoyable and building it into the working day to make it easier for people to engage in physical activity. 
WHO concluded that regular and adequate levels of physical activity in adults are a key determinant of energy expenditure, and thus fundamental to energy balance and weight control, in addition to a number of other health benefits.
The Scottish Intercollegiate Guideline Network guideline 115 on the management of obesity also recommends that prevention and weight reduction strategies should include both dietary change and promotion of increased levels of physical activity.