How Many Grams of Fat Per Day to Lose Weight?

How many grams of fat per day to lose weight is a common question, and the answer depends on your total calorie goal rather than a single fixed number. NHS guidance recommends that fat should make up no more than 35 percent of daily energy intake. On a typical weight-loss plan of 1,500 to 1,800 kilocalories per day, this translates to roughly 42 to 70 grams of fat daily. Understanding how fat compares to other macronutrients, which types to choose, and how to calculate a personal target can help you build a sustainable, evidence-based approach to losing weight.

How many grams of fat should you eat each day to lose weight?

On a 1,500 to 1,800 kilocalorie weight-loss diet, 42 to 70 grams of fat per day aligns with NHS guidance of 25 to 35 percent of total calories from fat. The exact target varies with your calorie goal, activity level and health status.

NHS guidance states that total fat should make up no more than 35 percent of daily energy intake.^[1][5] For a typical weight-loss diet of 1,500 to 1,800 kilocalories per day, keeping fat within 25 to 35 percent of total calories translates to approximately 42 to 70 grams of fat per day. Fat provides 9 kilocalories per gram, more than double the 4 kilocalories per gram supplied by carbohydrate or protein, so even modest reductions in fat intake can meaningfully lower overall energy consumption.^[1][4]

There is no single universal gram target because the right amount depends on your total calorie goal, body weight, activity level and any underlying health conditions. A person following a lower-calorie plan of around 1,200 kilocalories per day might aim for 33 to 47 grams of fat, while someone on a more moderate 2,000 kilocalorie plan could allow up to 78 grams. What matters most for weight loss is achieving a sustained calorie deficit, and fat intake is one lever among several.

Certain groups should seek clinical advice before restricting calories or dietary fat, including people who are pregnant, breastfeeding, under 18, underweight, or who have a history of eating disorders. For others managing weight through a structured clinical programme, a registered dietitian or prescribing clinician can calculate a personalised fat target based on a full dietary assessment. Bolt Pharmacy is a GPhC-registered UK online pharmacy offering online weight-management consultations, with prescriber review and pharmacist support, where clinically appropriate options may be discussed following assessment. Keeping a food diary, even briefly, helps most people understand where their fat calories are actually coming from before setting a specific daily target.

How does dietary fat affect weight loss compared to carbs and protein?

Fat contributes to weight gain or loss through calorie density rather than unique metabolic effects; all three macronutrients cause weight gain when consumed in surplus. Protein offers the greatest satiety and thermic effect, making it particularly useful for reducing overall intake.

Dietary fat contributes to weight gain or loss primarily through its calorie density rather than through any unique metabolic effect, meaning that a calorie surplus from fat is no more or less fattening than a surplus from carbohydrate or protein. That said, the three macronutrients do differ in how they influence hunger, hormones and body composition, which has practical implications for a weight-loss diet.

Protein has the highest thermic effect of the three macronutrients, meaning the body uses more energy to digest and metabolise it.^[17][18] Protein also promotes satiety more effectively than fat or carbohydrate, which can help reduce overall calorie intake without deliberate restriction. Carbohydrates vary considerably in their effect on appetite: refined, lower-fibre sources can cause more rapid rises and falls in blood glucose compared with wholegrains, pulses and vegetables, which slow digestion and support a more sustained feeling of fullness. Fat slows gastric emptying and can also prolong fullness after a meal. Choosing higher-fibre carbohydrate sources supports both satiety and overall diet quality.

Low-fat diets and low-carbohydrate diets have both been shown in clinical trials to produce meaningful weight loss when total calorie intake is reduced, and neither approach is definitively superior for long-term outcomes.^[14][15] The most effective dietary pattern is one that an individual can sustain. Reducing fat intake is a practical strategy for many people because fat is the most calorie-dense macronutrient, so cutting fatty foods tends to reduce calories efficiently. However, very low-fat diets that provide well below 20 percent of calories from fat risk impairing absorption of fat-soluble vitamins A, D, E and K, and may not supply adequate essential fatty acids; such approaches are not recommended without clinical supervision.^[19]

What types of fat should you choose or avoid on a weight loss diet?

Unsaturated fats from olive oil, oily fish, nuts and avocados should be prioritised, while saturated fats and artificial trans fats should be limited. All fats are equally calorie-dense, so choosing healthier sources improves diet quality without automatically reducing calories.

Unsaturated fats, found in foods such as olive oil, rapeseed oil, avocados, nuts, seeds and oily fish, are the types to prioritise on a weight-loss diet because they support cardiovascular health without the adverse effects associated with saturated and trans fats. Choosing healthier fat sources does not automatically reduce calorie intake, since all fats are equally energy-dense, but it does improve the nutritional quality of a calorie-controlled diet.

Saturated fats, present in butter, lard, full-fat dairy products, fatty cuts of meat, pastries and many processed foods, should be limited. NHS guidance recommends that saturated fat should account for no more than 10 percent of total daily energy intake.^[1][5] Eating too much saturated fat raises LDL cholesterol, which increases cardiovascular risk independently of body weight.^[3][6]

Trans fats, produced industrially through partial hydrogenation of vegetable oils, are the most harmful type.^[1][4] They raise LDL cholesterol and lower HDL cholesterol simultaneously.^[1][4] The UK food industry has largely removed artificial trans fats from products, but small amounts occur naturally in some meat and dairy foods. Checking ingredient labels for products listing "partially hydrogenated" oils remains a useful habit, even though such ingredients are now uncommon in UK-sold foods.

NHS guidance recommends eating at least two portions of fish per week, including at least one portion of oily fish such as salmon, mackerel or sardines, which provide beneficial omega-3 fatty acids. A standard portion is approximately 140 grams cooked weight.

In practical terms, useful swaps include:

• Replace butter with a small amount of olive or rapeseed oil spread

• Choose grilled, baked or steamed cooking methods over frying

• Select leaner cuts of meat and remove visible fat before cooking

• Include at least one portion of oily fish per week as part of your two weekly fish portions

• Snack on a small handful of unsalted nuts rather than crisps or biscuits

How do you work out your personal daily fat target?

Multiply your daily calorie target by 0.25 to 0.35, then divide by 9 to find your fat gram range; for example, a 1,600 kilocalorie plan at 30 percent fat gives approximately 53 grams per day. A GP or registered dietitian can adjust this if you have an underlying health condition.

Calculating your personal daily fat target begins with estimating your total daily calorie goal for weight loss, which is typically your estimated maintenance calorie requirement minus a deficit of around 500 to 600 kilocalories per day. NICE guidance on weight management supports this level of deficit as a basis for gradual, sustainable weight loss of approximately 0.5 kilograms per week. Once you have a calorie target, you can allocate a proportion to fat.

A practical approach is to aim for fat to provide 25 to 35 percent of your total daily calories. To convert this to grams, multiply your calorie target by the chosen percentage, then divide by 9 (the number of kilocalories per gram of fat). For example, on a 1,600 kilocalorie plan with 30 percent from fat: 1,600 multiplied by 0.30 equals 480 kilocalories from fat, divided by 9 equals approximately 53 grams of fat per day.

Several free tools can support this process. The NHS 12-week weight loss plan provides practical calorie targets and tracking guidance, and the British Dietetic Association's resources help estimate calorie needs based on age, sex, height, weight and activity level. Food tracking applications can then help you monitor actual fat intake against your target, though it is worth remembering that these tools provide estimates rather than precise measurements.

If you have a health condition such as type 2 diabetes, cardiovascular disease or a history of gallstones, your fat target may need to be adjusted by a healthcare professional. A GP or registered dietitian can provide personalised guidance. NHS referral to a structured weight management programme may be appropriate depending on your BMI (kg/m2) and clinical circumstances; eligibility thresholds and available services vary by locality and are determined by your local Integrated Care Board (ICB), so it is worth asking your GP what is available in your area.

What does NHS guidance say about fat intake for a healthy weight?

NHS guidance recommends no more than 70 grams of total fat and 20 grams of saturated fat daily for an average adult on 2,000 kilocalories. NICE emphasises a sustained calorie deficit within a multicomponent programme over targeting any single macronutrient.

NHS guidance recommends that total fat should make up no more than 35 percent of daily energy intake, with saturated fat kept below 10 percent of total energy, as part of a balanced diet that supports a healthy weight.^[1][5] For an average adult consuming 2,000 kilocalories per day, this equates to no more than 70 grams of total fat and no more than 20 grams of saturated fat daily.^[1][2] These figures are reflected in the reference intake values printed on UK food labels.

NICE guidance on obesity and weight management emphasises that dietary interventions should focus on achieving a sustained calorie deficit rather than prescribing a specific macronutrient ratio. NICE recommends that weight management support be delivered as part of a multicomponent programme that includes dietary advice, physical activity and behavioural support, rather than dietary change alone.^[11][12] Structured NHS weight management services are available in many areas, with eligibility and service structure determined locally by Integrated Care Boards; criteria and programme names can vary between regions and nations, so your GP is the best starting point for finding out what is available to you.

The NHS Eatwell Guide, which reflects current UK dietary recommendations, encourages people to choose unsaturated oils and spreads in small amounts, limit high-fat and high-sugar foods, and base meals around starchy carbohydrates, vegetables, fruit, lean protein and dairy or dairy alternatives. Reducing fat intake is one component of this framework, but the overall dietary pattern matters more than any single nutrient target. If you are unsure whether your current diet supports your weight goals, speaking to your GP or asking for a referral to a dietitian is a sensible first step.

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