Energy Balance: The Practical To-Do List
Energy Balance: what is worth doing, what is worth avoiding, and when to stop and see a doctor.
The relationship between energy taken in as food and energy used by the body. It is the mechanism underneath every weight change, and also the reason simple calorie arithmetic under-predicts what actually happens.
Key takeaways
- Adult daily guide, women: about 2,000 kcal
- Adult daily guide, men: about 2,500 kcal
- Most useful single change: Expect the deficit to shrink as you lose weight, and adjust.
- Commonest mistake: Assuming a fixed calorie target works indefinitely.
- See a doctor if any of the signs under "When to speak to a doctor" below apply to you.
Do
- Expect the deficit to shrink as you lose weight, and adjust
- Count drinks, which are easy to overlook and quick to add up
- Protect muscle with resistance training and adequate protein
- Use activity to support the deficit rather than to create all of it
Do not
- Assuming a fixed calorie target works indefinitely
- Treating exercise as licence to eat back more than it used
- Very large deficits, which reduce adherence and lean mass
The numbers behind the list
The reasoning behind both lists, in numbers.
| Measure | Figure |
|---|---|
| Adult daily guide, women | about 2,000 kcal |
| Adult daily guide, men | about 2,500 kcal |
| Alcohol | 7 kcal per gram |
| Largest component of daily energy use | basal metabolic rate |
| Adaptive change during a deficit | energy expenditure falls as weight falls |
If you change one thing
Expect the deficit to shrink as you lose weight, and adjust. That is the opening item above. Doing only that is still doing something.
Where to go next
- A Q and A on Energy Balance
- Energy Balance: Just the Figures
- Energy Balance — the reference entry
- Eating Out: What the Evidence Actually Says
- What the Guidance Really Says About Appetite and Satiety
When to speak to a doctor
See a GP for unexplained weight loss, or for weight change alongside excessive thirst, frequent urination or persistent fatigue. People on insulin or sulfonylureas need medical advice before creating a calorie deficit, because medication doses may need adjusting.
Where this comes from
- NHS — Understanding calories
- British Dietetic Association — weight management
How this page was put together
Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarised or generalised beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to a GP, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 999.
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